Anette Eleonora Gunnæs

• Gunnæs, Anette Eleonora; Tofan, Raluca; Berland, Kristian; Gorantla, Sandeep Madhukar; Storaas, Thomas Aarflot; Desissa, Temesgen Debelo; Schrade, Matthias; Persson, Clas; Einarsrud, Mari-Ann; Wiik, Kjell; Norby, Truls Eivind & Kanas, Nikola (2020). Chemical stability of Ca3Co4−xO9+δ/CaMnO3−δ p–n junction for oxide-based thermoelectric generators. RSC Advances.  ISSN 2046-2069.  10(9), s 5026- 5031 . doi: 10.1039/c9ra07159h Fulltekst i vitenarkiv. Vis sammendrag

  An all-oxide thermoelectric generator for high-temperature operation depends on a low electrical resistance of the direct p–n junction. Ca3Co4−xO9+δ and CaMnO3−δ exhibit p-type and n-type electronic conductivity, respectively, and the interface between these compounds is the material system investigated here. The effect of heat treatment (at 900 °C for 10 h in air) on the phase and element distribution within this p–n junction was characterized using advanced transmission electron microscopy combined with X-ray diffraction. The heat treatment resulted in counter diffusion of Ca, Mn and Co cations across the junction, and subsequent formation of a Ca3Co1+yMn1−yO6 interlayer, in addition to precipitation of Co-oxide, and accompanying diffusion and redistribution of Ca across the junction. The Co/Mn ratio in Ca3Co1+yMn1−yO6 varies and is close to 1 (y = 0) at the Ca3Co1+yMn1−yO6–CaMnO3−δ boundary. The existence of a wide homogeneity range of 0 ≤ y ≤ 1 for Ca3Co1+yMn1−yO6 is corroborated with density functional theory (DFT) calculations showing a small negative mixing energy in the whole range.

• Gutterød, Emil Sebastian; Pulumati, S.H.; Kaur, Gurpreet; Lazzarini, Andrea; Solemsli, Bjørn Garding; Gunnæs, Anette Eleonora; Ahoba-Sam, Christian; Kalyva, Maria Evangelou; Sannes, Johnny Andreas; Svelle, Stian; Skúlason, Egill; Nova, Ainara & Olsbye, Unni (2020). Influence of Defects and H2O on the Hydrogenation of CO2 to Methanol over Pt Nanoparticles in UiO-67 Metal-Organic Framework. Journal of the American Chemical Society.  ISSN 0002-7863.  142(40), s 17105- 17118 . doi: 10.1021/jacs.0c07153 Fulltekst i vitenarkiv.
• Kalyva, Maria Evangelou; Sunding, Martin Fleissner; Gunnæs, Anette Eleonora; Diplas, Spyridon & Redekop, Evgeniy (2020). Correlation between surface chemistry and morphology of PtCu and Pt nanoparticles during oxidation-reduction cycle. Applied Surface Science.  ISSN 0169-4332.  532, s 1- 6 . doi: 10.1016/j.apsusc.2020.147369 Fulltekst i vitenarkiv. Vis sammendrag

  Process conditions during catalytic reactions induce significant changes in surface chemistry and structure of bi- (mono) metallic nanoparticles leading to their deactivation, and this can ultimately affect the reactions long-term performance. Here PtCu and Pt model nanoparticles are prepared by microwave synthesis and characterized by X-ray diffraction (XRD). Surface chemical and morphological changes of the nanoparticles during high-temperature oxidation and reduction treatments cycle are correlated by near in situ X-ray photoelectron spectroscopy (XPS) and ex situ transmission electron microscopy (TEM) - energy-dispersive X-ray spectroscopy (EDS) studies. At 300 °C the surface atomic composition of the PtCu nanoparticles switches reversibly upon the cycle and at the same time their morphology and composition are maintained. At 400 °C, the surface atomic composition does not fully restore and, while the shape is maintained, the size and composition are not. This occurs by a mechanism of Cu leaching out from the nanoparticles. These data delineate potential operating conditions for stable PtCu nanocatalysts.

• Poulia, Anthoula; S. Azar, Amin; Svec, Peter; Bazioti, Kalliopi; Belle, Branson; Gunnæs, Anette Eleonora; Diplas, Spyridon & Mikheenko, Pavlo (2020). Nanoscale Magnetic Properties of Additively Manufactured FeCoNiAlxMnx High-Entropy Alloys, In  2020 IEEE 10th International Conference on “Nanomaterials: Applications & Properties” (NAP – 2020).  IEEE.  ISBN 978-1-7281-8506-4.  Article.  s 01NMM02-1 - 01NMM02-5 Fulltekst i vitenarkiv. Vis sammendrag

  Magnetic properties of High-Entropy Alloys based on the Fe-Co-Ni-Al-Mn system are reported. High-Entropy Alloys are cutting-edge technological materials containing five or more elements in relatively high concentrations (5–35 at.%) within one or several solid-state solutions. These solutions are stabilized at the nanometer scale due to the high contribution of the mixing entropy to the Gibbs free energy, which can overcome the enthalpic contribution. Two magnetic alloys are found in FeCoNiAlxMnx (1.6 at.%  x  7.8 at.%) samples processed by laser metal deposition. The magnetic techniques used to screen the materials were magneto-optical imaging and magnetic force microscopy. The former allows characterizing magnetic properties within the mm-μm scale, while the latter is efficient down to the nanometer scale. Magnetic screening confirms the importance of the nanostructure in defining magnetic properties of the alloys, and the trends in the magnetic behavior as a function of the alloy composition are revealed. The experimental results suggest that it is possible to form unique alloys, which may outperform conventional magnetic materials used in a variety of applications such as transformers, screening shields and wind power generators.

• Wachowski, Sebastian Lech; Szpunar, Iga; Sørby, Magnus Helgerud; Mielewczyk-Gryń, Aleksandra; Balaguer, Maria; Ghica, Corneliu; Istrate, Marian Cosmin; Gazda, Maria; Gunnæs, Anette Eleonora; Serra, José M.; Norby, Truls Eivind & Strandbakke, Ragnar (2020). Structure and water uptake in BaLnCo2O6−δ (Ln = La, Pr, Nd, Sm, Gd, Tb and Dy). Acta Materialia.  ISSN 1359-6454.  199, s 297- 310 . doi: 10.1016/j.actamat.2020.08.018 Fulltekst i vitenarkiv.
• Guzik, Matylda N.; Schrade, Matthias; Tofan, Raluca; Almeida Carvalho, Patricia; Berland, Kristian; Sørby, Magnus Helgerud; Persson, Clas; Gunnæs, Anette Eleonora & Hauback, Bjørn (2019). Long- and short-range structures of Ti1-xHfxNi1.0/1.1Sn half-Heusler compounds and their electric transport properties. CrysteEngComm.  ISSN 1466-8033.  21, s 3330- 3342 . doi: 10.1039/c9ce00046a Fulltekst i vitenarkiv.
• Bundli, Silje; Dhak, Prasanta; Jensen, Martin; Gunnæs, Anette Eleonora; Nguyen, Phuong Dan; Fjellvåg, Helmer & Sjåstad, Anja Olafsen (2019). Controlled alloying of Pt-Rh nanoparticles by the polyol approach. Journal of Alloys and Compounds.  ISSN 0925-8388.  779, s 879- 885 . doi: 10.1016/j.jallcom.2018.11.301
• Hjelmeland, Trude Bjørgås; Bazioti, Kalliopi; Gunnæs, Anette Eleonora; Volkov, Y & Mikheenko, Pavlo (2019). Effect of colossal magnetoresistance material La0.67Ca0.33MnO3 on superconducting properties of YBa2Cu3O7-δ thin films. Journal of Magnetism and Magnetic Materials.  ISSN 0304-8853.  487 . doi: 10.1016/j.jmmm.2019.165335 Fulltekst i vitenarkiv.
• Molino, Andrea; Holzinger, J.; Lukaszuk, Katarzyna Anna; Rojo-Gama, Daniel; Gunnæs, Anette Eleonora; Skibsted, J.; Lundegaard, Lars Fahl; Svelle, Stian; Beato, Pablo; Bordiga, Silvia & Lillerud, Karl Petter (2019). Synthesis of ZSM-23 (MTT) zeolites with differentcrystal morphology and intergrowths: effects onthe catalytic performance in the conversion ofmethanol to hydrocarbons. Catalysis Science & Technology.  ISSN 2044-4753.  9(23), s 6782- 6792 . doi: 10.1039/c9cy01068h Fulltekst i vitenarkiv.
• Oyama, Kohei; Diplas, Spyridon; M'hamdi, Mohammed; Gunnæs, Anette Eleonora & S. Azar, Amin (2019). Heat source management in wire-arc additive manufacturing process for Al-Mg and Al-Si alloys. Additive Manufacturing.  ISSN 2214-8604.  26, s 180- 192 . doi: 10.1016/j.addma.2019.01.007 Fulltekst i vitenarkiv. Vis sammendrag

  Modelling of wire-arc additive manufacturing process is an effective way for adapting the optimum parameters as well as understanding and managing the sequences of layer-by-layer deposition. Some of these parameters such as toolpath, deposition intervals and heat source power play important roles in improving the process viability and cost efficiency. In this article, we have studied Al-5Mg, Al-3Si alloys as demonstrators, from both experimental and modelling perspectives, to benchmark different deposition parameters and provided guidelines for optimising the process conditions. Physical values such as total distortion and residual stress were selected as indicators for the manufacturability of the structure. The simulations were performed by Simufact Welding software, that is outfitted with the MARC solver and the experiments were executed in a robotic cell. We have introduced a method for optimising the process parameters based on the heat source power modification and selection of unique parameters for each deposition layer. This was performed by monitoring the evolution of the molten pool size and geometry when building a wall structure. The results suggest that achieving an uninterrupted deposition process entails modification of the heat input for each layer. Thus, a simple analytical method was proposed to estimate the heat input reduction coefficient for a wall structure as a function of molten pool geometry and the height at which, a new layer is being deposited. It was also shown that a generic selection of parameters for aluminium alloys may impair the eventual quality for some of the alloys due to their inherent physical properties such as high temperature flowability.

• Bergum, Kristin; Riise, Heine Nygard; Gorantla, Sandeep Madhukar; Lindberg, Per; Jensen, Ingvild Julie Thue; Gunnæs, Anette Eleonora; Galeckas, Augustinas; Diplas, Spyridon; Svensson, Bengt Gunnar & Monakhov, Edouard (2018). Improving carrier transport in Cu2O thin films by rapid thermal annealing. Journal of Physics: Condensed Matter.  ISSN 0953-8984.  30(7) . doi: 10.1088/1361-648X/aaa5f4
• Guzik, Matylda N.; Echevarria-Bonet, Cristina; Riktor, Marit Dalseth; Almeida Carvalho, Patricia; Gunnæs, Anette Eleonora; Sørby, Magnus Helgerud & Hauback, Bjørn (2018). Half-Heusler phase formation and Ni atom distribution in M-Ni-Sn (M = Hf, Ti, Zr) systems. Acta Materialia.  ISSN 1359-6454.  148, s 216- 224 . doi: 10.1016/j.actamat.2018.01.019 Fulltekst i vitenarkiv.
• Jensen, Ingvild Julie Thue; Gorantla, Sandeep Madhukar; Løvvik, Ole Martin; Gan, Jiantuo; Nguyen, Phuong Dan; Monakhov, Edouard; Svensson, Bengt Gunnar; Gunnæs, Anette Eleonora & Diplas, Spyridon (2017). Interface phenomena in magnetron sputtered Cu2O/ZnO heterostructures. Journal of Physics: Condensed Matter.  ISSN 0953-8984.  29(43) . doi: 10.1088/1361-648X/aa8799 Fulltekst i vitenarkiv.
• Lindberg, Per Filip; Gorantla, Sandeep Madhukar; Gunnæs, Anette Eleonora; Svensson, Bengt Gunnar & Monakhov, Edouard (2017). Electronic properties and morphology of copper oxide/n-type silicon heterostructures. Journal of Physics: Condensed Matter.  ISSN 0953-8984.  29(31) . doi: 10.1088/1361-648X/aa77bc
• Schrade, Matthias; Berland, Kristian; Eliassen, Simen Nut Hansen; Guzik, Matylda Natalia; Echevarria-Bonet, Cristina; Sørby, Magnus Helgerud; Jenus, Petra; Hauback, Bjørn; Tofan, Raluca; Gunnæs, Anette Eleonora; Persson, Clas; Løvvik, Ole Martin & Finstad, Terje (2017). The role of grain boundary scattering in reducing the thermal conductivity of polycrystalline XNiSn (X=Hf, Zr, Ti) half-Heusler alloys. Scientific Reports.  ISSN 2045-2322.  7 . doi: 10.1038/s41598-017-14013-8 Fulltekst i vitenarkiv.
• Gan, Jiantuo; Gorantla, Sandeep Madhukar; Riise, Heine Nygard; Fjellvåg, Øystein Slagtern; Diplas, Spyridon; Løvvik, Ole Martin; Svensson, Bengt Gunnar; Monakhov, Edouard & Gunnæs, Anette Eleonora (2016). Structural properties of Cu2O epitaxial films grown on c-axis single crystal ZnO by magnetron sputtering. Applied Physics Letters.  ISSN 0003-6951.  108:152110(15), s 1- 5 . doi: 10.1063/1.4945985 Vis sammendrag

  Epitaxial Cu2O films grown by reactive and ceramic radio frequency magnetron sputtering on single crystalline ZnO (0001) substrates are investigated. The films are grown on both O- and Zn-polar surface of the ZnO substrates. The Cu2O films exhibit a columnar growth manner apart from a ∼5 nm thick CuO interfacial layer. In comparison to the reactively sputtered Cu2O, the ceramic-sputtered films are less strained and appear to contain nanovoids. Irrespective of polarity, the Cu2O grown by reactive sputtering is observed to have (111)Cu2O||(0001)ZnO epitaxial relationship, but in the case of ceramic sputtering the films are found to show additional (110)Cu2O reflections when grown on O-polar surface. The observed CuO interfacial layer can be detrimental for the performance of Cu2O/ZnO heterojunction solar cells reported in the literature.

• Gunnæs, Anette Eleonora; Gorantla, Sandeep Madhukar; Løvvik, Ole Martin; Gan, Jiantuo; Carvalho, Patricia; Svensson, Bengt Gunnar; Monakhov, Edouard; Bergum, Kristin; Jensen, Ingvild Julie Thue & Diplas, Spyridon (2016). Epitaxial strain-induced growth of CuO at Cu2O/ZnO interfaces. Journal of Physical Chemistry C.  ISSN 1932-7447.  120(41), s 23552- 23558 . doi: 10.1021/acs.jpcc.6b07197 Vis sammendrag

  Cu2O/ZnO has been envisaged as a potential material system for the next generation thin film solar cells. So far, the experimental efforts to obtain conversion efficiencies close to the theoretically predicted value have failed. Combining aberration-corrected (scanning) transmission electron microscopy and density functional theory modelling, we have studied the interfaces between single crystal c-axis oriented ZnO and high-quality magnetron sputtered Cu2O films. Strikingly, our study shows that the first ~5 nm of the Cu-oxide films have the structure of the monoclinic CuO phase. The CuO layer is textured with the (111), (11¯1), (¯111), (1¯1 ¯1), (¯1 ¯11), (1¯11), (¯11¯1) and (100) planes parallel to the (0001) and (000¯1) ZnO interfaces. The ionic arrangement on these planes resembles the hexagonal arrangement of the ZnO interface and epitaxy exists across the interface. A continued epitaxial growth of [111] oriented Cu2O follows resulting in epitaxial 180o rotation twins in the Cu2O layer. For the case with the (100)CuO interfacial plane we have: (111)[1¯10]Cu2O II (100)[011]CuO II (0001)[11¯20]ZnO. Because of a closer lattice matching of CuO with ZnO and Cu2O, the total strain and energy is reduced compared to a pure (111)Cu2O II (0001)ZnO interface. The existence of CuO is anticipated to be a contributing factor for the low conversion efficiencies obtained experimentally.

• Song, Xin; Valset, Kjetil; Graff, Joachim Seland; Thøgersen, Annett; Gunnæs, Anette Eleonora; Luxsacumar, Sivakanesar; Løvvik, Ole Martin; Snyder, Jeffrey G. & Finstad, Terje (2015). Nanostructuring of undoped ZnSb by Cryo-Milling. Journal of Electronic Materials.  ISSN 0361-5235.  44(8), s 2578- 2584 . doi: 10.1007/s11664-015-3708-6 Vis sammendrag

  We report the preparation of nanosized ZnSb powder by cryo-milling. The effect of cryo-milling then hot-pressing of undoped ZnSb was investigated and compared with that of room temperature ball-milling and hot-pressing under different temperature conditions. ZnSb is a semiconductor with favorable thermoelectric properties when doped. We used undoped ZnSb to study the effect of nanostructuring on lattice thermal conductivity, and with little contribution at room temperature from electronic thermal conductivity. Grain growth was observed to occur during hot-pressing, as observed by transmission electron microscopy and x-ray diffraction. The thermal conductivity was lower for cryo-milled samples than for room-temperature ball-milled samples. The thermal conductivity also depended on hot-pressing conditions. The thermal conductivity could be varied by a factor of two by adjusting the process conditions and could be less than a third that of single-crystal ZnSb.

• Hage, Fredrik Sydow; Kepaptsoglou, Despoina Maria; Seabourne, Ché Royce; Ramasse, Quintim M.; Scott, Andrew J.; Prytz, Øystein; Gunnæs, Anette Eleonora & Helgesen, Geir (2014). Dielectric response of pentagonal defects in multilayer graphene nano-cones. Nanoscale.  ISSN 2040-3364.  6(3), s 1833- 1839 . doi: 10.1039/c3nr05419e
• Nguyen, Phuong Dan; Gunnæs, Anette Eleonora; Sunding, Martin Fleissner & Olsen, Arne (2014). Heterogeneous nucleation and growth of CrSi2 in sputtered thin films of silicon/silicon nitride. Thin Solid Films.  ISSN 0040-6090.  556, s 200- 205 . doi: 10.1016/j.tsf.2014.01.080
• Bleken, Bjørn Tore Lønstad; Wragg, David; Arstad, Bjørnar; Gunnæs, Anette Eleonora; Mouzon, Johanne; Helveg, Stig; Lundegaard, Lars Fahl; Beato, Pablo; Bordiga, Silvia; Olsbye, Unni; Svelle, Stian & Lillerud, Karl Petter (2013). Unit cell thick nanosheets of zeolite H-ZSM-5: Structure and activity. Topics in catalysis.  ISSN 1022-5528.  56(9-10), s 558- 566 . doi: 10.1007/s11244-013-0010-9 Vis sammendrag

  Nanosheets of zeolite H-ZSM-5 were synthesized and characterized by X-ray diffraction, transmission electron microscopy (TEM), N2-physisorption, FT-IR spectroscopy, 27Al and 29Si MAS NMR spectroscopy in addition to catalytic testing in conversion of methanol to hydrocarbons (MTH). It was found that Rietveld analysis, involving anisotropic broadening parameters, gave average crystallite dimensions in good agreement with TEM images. The selectivities in MTH is intact in the mesoporous nanosheet H-ZSM-5 with the largest difference being a higher C3/C2 ratio compared to regular H-ZSM-5.

• Hage, Fredrik Sydow; Ramasse, Quentin; Kepaptsoglou, Despoina Maria; Prytz, Øystein; Gunnæs, Anette Eleonora; Helgesen, Geir & Brydson, Rik (2013). Topologically induced confinement of collective modes in multilayer graphene nanocones measured by momentum-resolved STEM-VEELS. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  88(15) . doi: 10.1103/PhysRevB.88.155408
• Hadidi, Kianoosh; Hancke, Ragnhild; Norby, Truls; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2012). Atomistic study of LaNbO4; surface properties and hydrogen adsorption. International Journal of Hydrogen Energy.  ISSN 0360-3199.  37(8), s 6674- 6685 . doi: 10.1016/j.ijhydene.2012.01.065 Vis sammendrag

  We have calculated fundamental properties of pure and hydrogen-covered (010), (101), (100) and (001) surfaces of the low temperature monoclinic phase of LaNbO4 (LN). The (010) surface was the most stable one, exhibiting electronic structure and local geometric configurations similar to bulk. As the first stage of proton migration into the electrolyte, the ability of LN surfaces to split H2 molecules was probed indirectly by calculating the adsorption energy of H atoms on two of the LN surfaces. H adsorption on the (010) surface was found to be strongly endothermic, and thus cannot contribute much in splitting H2. The adsorption energy on the relatively unstable (101) surface was on the other hand approximately −0.6 eV, in the right range for surface H2 to be catalyzed beneficially. H adsorption on this surface was induced by surface states in the band gap of the clean surface. Since the unstable (101) surface is not abundant, the rate of dissociative adsorption of H2 on the LN surface can be anticipated to be very low. Application of the energies to simple adsorption isotherm calculations for typical proton conducting fuel cells (PCFCs) operating temperatures correspondingly showed very low H coverage, and it is not expected that LaNbO4 surfaces can contribute much to the H2 activation reaction of a PCFC anode.

• Hadidi, Kianoosh; Norby, Truls; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2012). Hydrogen energetics and charge transfer in the Ni/LaNbO4 interface from DFT calculations. International Journal of Hydrogen Energy.  ISSN 0360-3199.  37(9), s 8033- 8042 . doi: 10.1016/j.ijhydene.2011.11.032 Vis sammendrag

  Calculations based on density functional theory have been used to simulate interface structures between the tetragonal and monoclinic phases of LaNbO4 (LN) and Ni. Schottky barrier heights were calculated using the interface electronic structure; they were 3.0 and 1.8 eV for p- and n-type barriers. The hydrogen interstitials were found to be significantly higher stable in the LN part of the interface than in bulk LN. Also, the potential energy curve of hydrogen diffusion from Ni into LN exhibited a deep well of around 2 eV, located in the gap region between two components. The stability of H atom in the gap region and interfacial layers of LN is explained by metal-induced gap states and indicates that there will be an accumulation of hydrogen in this area. It was shown that hydrogen is ionized when enters from Ni to the LN interfacial layer, approaching to the O atoms and that the electron lost from hydrogen resides in the interface states, located in the band gap of LN.

• Kepaptsoglou, Despoina Maria; Hadidi, Kianoosh; Løvvik, Ole Martin; Magraso, Anna; Norby, Truls; Gunnæs, Anette Eleonora; Olsen, Arne & Ramasse, Quentin (2012). Interfacial Charge Transfer and Chemical Bonding in a Ni-LaNbO4 Cermet for Proton-Conducting Solid-Oxide Fuel Cell Anodes. Chemistry of Materials.  ISSN 0897-4756.  24(21), s 4152- 4159 . doi: 10.1021/cm302317f Vis sammendrag

  In this work, we present an atomic scale study of the structural and chemical characteristics of interfaces between Ni and LaNbO4 grains in Ni–LaNbO4 cermets, a model composite material for anodes in proton-conducting solid-oxide fuel cells (SOFC). Electron energy loss spectroscopy (EELS) performed in an aberration-corrected scanning transmission electron microscope reveals the absence of reaction or interdiffusion layers at the interface. Changes in the valence state of Ni as well as in the electronic structure of La, reflected by changes in the EELS fine features at the interface, are shown to be related to charge transfer across the interface. The experimental results are in excellent agreement with ab initio calculations based on density functional theory, which predict that direct chemical bonds are formed between the metal and the ceramic at this abrupt interface, resulting in a redistribution of electronic charge across the interface.

• Magraso Sola, Anna; Frontera, Carlos; Gunnæs, Anette Eleonora; Tarancon, Albert; Marrero-López, David; Norby, Truls & Haugsrud, Reidar (2011). Structure, chemical stability and mixed proton-electron conductivity in BaZr0.9-xPrxGd0.1O3-delta. Journal of Power Sources.  ISSN 0378-7753.  196(22), s 9141- 9147 . doi: 10.1016/j.jpowsour.2011.06.076
• Sunding, Martin Fleissner; Hadidi, Kianoosh; Diplas, Spyridon; Løvvik, Ole Martin; Norby, Truls & Gunnæs, Anette Eleonora (2011). XPS characterisation of in situ treated lanthanum oxide and hydroxide using tailored charge referencing and peak fitting procedures. Journal of Electron Spectroscopy and Related Phenomena.  ISSN 0368-2048.  184(7), s 399- 409 . doi: 10.1016/j.elspec.2011.04.002
• Diplas, Spyridon; Løvvik, Ole Martin; Nordmark, Heidi; Kepaptsoglou, Despoina Maria; Graff, Joachim Seland; Ladam, Cecile; Tyholdt, Frode; Walmsley, John; Gunnæs, Anette Eleonora; Fagerberg, Ragnar & Ulyashin, Alexander (2010). Characterization of thin and ultrathin transparent conducting oxide (TCO) films and TCO-Si interfaces with XPS, TEM and ab initio modeling. Surface and Interface Analysis.  ISSN 0142-2421.  42(6-7), s 874- 877 . doi: 10.1002/sia.3355
• Sunding, Martin Fleissner; Kepaptsoglou, Despoina Maria; Diplas, Spyridon; Norby, Truls & Gunnæs, Anette Eleonora (2010). XPS characterisation of the interface between anode and electrolyte in a proton conducting solid oxide fuel cell. Surface and Interface Analysis.  ISSN 0142-2421.  42(6-7), s 568- 571 . doi: 10.1002/sia.3383
• Prytz, Øystein; Gunnæs, Anette Eleonora; Karlsen, Ole Bjørn; Breivik, Tallak Harald; Toberer, E. S.; Snyder, G. J. & Taftø, Johan (2009). Nanoscale inclusions in the phonon glass thermoelectric material Zn4Sb3. Philosophical Magazine Letters.  ISSN 0950-0839.  89(6), s 362- 369 . doi: 10.1080/09500830902950464
• Diplas, Spyridon; Knutsen, T; Jørgensen, Sissel; Gunnæs, Anette Eleonora; Våland, T.; Norby, Truls; Olsen, Arne & Taftø, Johan (2008). An experimental study of the electronic structure of anodically grown films on an amorphous Ni78Si8B14 alloy. Surface and Interface Analysis.  ISSN 0142-2421.  40(3-4), s 826- 829 . doi: 10.1002/sia.2748
• Fjeld, Harald; Haugsrud, Reidar; Gunnæs, Anette Eleonora & Norby, Truls (2008). Proton and oxide ion conductivity in the grain interior and grain boundaries of Ca-doped Er₂Ti₂O₇ with Si impurities. Solid State Ionics.  ISSN 0167-2738.  179(33-34), s 1849- 1853
• Polychronopoulou, K; Neidhardt, J; Rebholz, C; Baker, MA; O'Sullivan, M; Reiter, AE; Gunnæs, Anette Eleonora; Giannakopoulos, K & Mitterer, C (2008). Synthesis and characterization of Cr-B-N coatings deposited by reactive arc evaporation. Journal of Materials Research.  ISSN 0884-2914.  23(11), s 3048- 3055 . doi: 10.1557/JMR.2008.0370
• Tonheim, C.R.; Selvig, E.; Nicolas, S.; Gunnæs, Anette Eleonora; Breivik, M & Haakenaasen, R (2008). Excitation density dependence of the photoluminescence from CdxHg1-xTe multiple quantum wells. Journal of Physics: Conference Series (JPCS).  ISSN 1742-6588.  100, s 042024 . doi: 10.1088/1742-6596/100/4/042024
• Breivik, Tallak Harald; Diplas, Spyridon; Ulyashin, A. G.; Gunnæs, Anette Eleonora; Olaisen, Birger Retterstøl; Holt, Arve; Olsen, Arne & Wright, Daniel Nilsen (2007). Nano-structural properties of ZnO films for Si based heterojunction solar cells. Thin Solid Films.  ISSN 0040-6090.  515, s 8479- 8483 . doi: 10.1016/j.tsf.2007.03.095
• Diplas, Spyridon; Ulyashin, Alexander; Maknys, Kestutis; Gunnæs, Anette Eleonora; Jørgensen, Sissel; Watts, J.F.; Olsen, Arne; Finstad, Terje & Wright, Daniel Nilsen (2007). On the processing-structure-property relationship of ITO layers deposited on crystalline and amorphous Si. Thin Solid Films.  ISSN 0040-6090.  515, s 8539- 8543 . doi: 10.1016/j.tsf.2007.03.091 Vis sammendrag

  Indium-tin-oxide(ITO)antireflection coatings were deposited on crystalline Si(c-Si), amorphoushydrogenatedSi(a-Si:H)and glass substrates at room temperature(RT), 160 °C and 230 °C by magnetron sputtering. The films were characterised using atomic force microscopy, transmission electron microscopy, angle resolved X-ray photoelectron spectroscopy, combined with resistance and transmittance measurements. The conductivity and refractive index as well as the morphology of the ITO films showed a significant dependence on the processing conditions. The films deposited on the two different Si substrates at higher temperatures have rougher surfaces compared to the RT ones due to the development of crystallinity and growth of columnar grains.

• Tyholdt, Frode; Fjellvåg, Helmer; Gunnæs, Anette Eleonora & Olsen, Arne (2007). Synthesis of epitaxial BiFeO3 films by chemical solution deposition on Pt(100). Journal of Applied Physics.  ISSN 0021-8979.  102 . doi: 10.1063/1.2784999 Vis sammendrag

  Thin (012) oriented epitaxial films of rhombohedral (R3c) BiFeO3, ~120 nm thickness, were obtained by means of chemical solution deposition on MgO(100)/Pt(100) substrates using an alkoxide based precursor system. X-ray diffraction and transmission electron microscopy (TEM) analysis confirmed good epitaxial matching to the substrate. The results show that careful control of the bismuth excess used for counterbalancing evaporation during crystallization is required. In contrast to lead-containing systems such as PZT, where Pb is pushed to the surface by the crystallization front where it evaporates, the Bi excess forms a Bi-rich phase at the BiFeO3/Pt interface. This phase is believed to represent a Fe substituted version of the high temperature phase -Bi2O3. TEM analysis shows that this phase grows on the substrate with (111) and (001) orientation. It is further found that BiFeO3 grows with (012) orientation on this phase as well, making an overall epitaxial film of BiFeO3 possible. Crystallization theory was applied to explain the presence of a Bi-rich secondary phase.

• Christensen, Jens S.; Kuznetsov, Andrej; Gunnæs, Anette Eleonora; Svensson, Bengt Gunnar & Radamson, H.H. (2006). Phosphorus diffusion in the presence of threading dislocations in strain relaxed SiGe films. Materials Science in Semiconductor Processing.  ISSN 1369-8001.  9, s 650- 654
• Heng, Chenglin; Li, Yanjun; Mayandi, Jeyanthinath; Finstad, Terje; Jørgensen, Sissel; Gunnæs, Anette Eleonora; Olsen, Arne & Storås, P. (2006). A study on the precipitation of Ge-rich nanoparticles in a luminescent (Er, Ge) co-doped SiO2 film sputtered with Ar+O2 plasma. International Journal of Nanoscience.  ISSN 0219-581X.  5(4-5), s 493- 498 . doi: 10.1142/S0219581X06004681 Vis sammendrag

  We report the photoluminescence (PL) from an (Er, Ge) co-doped SiO2 film deposited by rf-magnetron sputtering in an Ar + O2 ambience. The sample film was annealed in N2 for 30 min at different temperatures. The PL intensity increases as the annealing temperature increases from 700 to 1000°C, and drops to very weak after 1100°C annealing. High-resolution transmission electron microscopy (TEM) observation shows that there are some Ge-rich nanoparticles precipitated after 700°C annealing, and more clusters precipitated after 1000°C annealing. However, no Ge nanocrystals were found in these films, the diffraction patterns are always halo which indicates that the precipitated clusters are in amorphous states. X-ray photoelectron spectroscopy (XPS) analysis indicates the Ge in the nanoclusters is mostly in an oxidized state and the oxidation state of Er increases with increasing annealing temperature.

• Sørby, Magnus; Gunnæs, Anette Eleonora; Løvvik, Ole Martin; Brinks, H. W.; Fjellvåg, Helmer & Hauback, Bjørn (2006). The crystal structure of Zr2NiD4.5. Acta Crystallographica Section B: Structural Science.  ISSN 0108-7681.  62, s 972- 978
• Gunnæs, Anette Eleonora; Skogstad, Asbjørn; Olsen, Arne & Erik, Bye (2005). Morphology and structure of airborn beta-SiC fibres produced during the industrial production of non-fibrous silicon carbide. Journal of Materials Science.  ISSN 0022-2461.  40, s 6011- 6017

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• Poulia, Anthoula; S. Azar, Amin; Svec, Peter; Bazioti, Kalliopi; Belle, Branson; Gunnæs, Anette Eleonora; Diplas, Spyros & Mikheenko, Pavlo (2020). Nanoscale Magnetic Properties of Additively Manufactured FeCoNiAlxMnx High-Entropy Alloys. Vis sammendrag

  Magnetic properties of High-Entropy Alloys based on the Fe-Co-Ni-Al-Mn system are reported. High-Entropy Alloys are cutting-edge technological materials containing five or more elements in relatively high concentrations (5–35 at.%) within one or several solid-state solutions. These solutions are stabilized at the nanometer scale due to the high contribution of the mixing entropy to the Gibbs free energy, which can overcome the enthalpic contribution. Two magnetic alloys are found in FeCoNiAlxMnx (1.6 at.%  x  7.8 at.%) samples processed by laser metal deposition. The magnetic techniques used to screen the materials were magneto-optical imaging and magnetic force microscopy. The former allows characterizing magnetic properties within the mm-μm scale, while the latter is efficient down to the nanometer scale. Magnetic screening confirms the importance of the nanostructure in defining magnetic properties of the alloys, and the trends in the magnetic behavior as a function of the alloy composition are revealed. The experimental results suggest that it is possible to form unique alloys, which may outperform conventional magnetic materials used in a variety of applications such as transformers, screening shields and wind power generators.

• Solemsli, Bjørn Gading; Olsbye, Unni; Gunnæs, Anette Eleonora & Gutterød, Emil Sebastian (2020). A Study of Catalytic Pt Nanoparticles inside a Nano-porous Functionalized UiO MOF-matrix for CO2-Hydrogenation. Vis sammendrag

  Hydrogenation of carbon dioxide hasreceivedincreasingattentionin catalytic research the last decade as a sustainable alternativeforproducing high value chemicals thattodayare produced fromfossil fuels. The aim of this thesis has been two-fold: First, to study Pt nanoparticles formed in various UiO-66 and -67 metal-organic frameworks (MOFs) by Transmission Electron Microscopy (TEM), and second, to study the Pt-containing MOFs as catalysts for the CO2hydrogenation reaction.Three Zr-based UiO-66 MOF and nineUiO-67 MOF samples containing different amountsof functionalized linkers were impregnated withdifferent amounts ofK2PtCl4and reduced in H2at 350 ̊C for 4 hours to form Pt nanoparticles embedded in the MOF matrix.The samples were then testedin a H2/CO2feed at 8 bar and 170 ̊Cfor the hydrogenation reaction. After testing,TEMwas used to investigate the formation of Pt nanoparticles andtheir relationship with the surrounding MOF structure. The study revealed that, despite variable the linkers in the MOF,the conversion of CO2isdominated bythe reverse water-gas shift reaction,suggestingthat the linkers donot partakethe reactions mechanisms. Analysis usingTEMrevealedthat the Pt nanoparticles grow independently of its surroundings inside the MOFs with no observable growth relationshipwith the MOF. The nanoparticles are seen to grow into octahedral crystals that are larger than the pores in the framework. Samples with different amountsof missing linker type defects show that the presence of open Zr-node sitesenhances the selectivity towards methanol. A sample of Pt-functionalized UiO-67 with 10% [2,2’-bipyridine]5,5’-dicaboxylicacidlinker was oxidised toinduce missing linkerdefects post synthetically. After reduction in H2at 350 ̊C for 4 hours, the sample was oxidized in situin synthetic air for three different time spans. Careful analysis with N2-adsroption and TEM revealedthat the structure of the MOF deteriorates and loses accessible surface area with increasing timeon steam, while keeping the dispersion of the Pt nanoparticles. PXRD analysis revealedthe formation of tetragonal ZrO2. Extensive testsfrom 1-30 bar and 170-375 ̊C reveal a lower conversion and higher selectivity towards methanol for a fully calcined sample, indicating that the Zr-nodes behave similarlyto non-MOF ZrO2supports. Transient kinetic studies of the parent UiO-67 sample revealedthat the sample behaves similarlytopreviously studied systemsby Gutterød et al., and showed the presence of an inverse kinetic isotope effect for methane and methanolformation upon H2/D2exchange.

• Kalyva, Maria Evangelou; Redekop, Evgeniy; Johansson, Niclas; Urpelainen, Samuli; Gunnæs, Anette Eleonora; Diplas, Spyridon & Olsbye, Unni (2019). AP-XPS study of bimetallic PtCu nanoparticles supported on SiO2 films.
• Fjellvåg, Øystein; Sjåstad, Anja Olafsen & Gunnæs, Anette Eleonora (2019). Oxyhydrides - Synthesis, Crystal Structure and Properties. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 2153.
• Løberg, Monika; Karlsen, Ole Bjørn; Løvvik, Ole Martin; Almeida Carvalho, Patricia & Gunnæs, Anette Eleonora (2019). Characterization of phase transformations within the Cu-Pd-Sn system - a possible shape memory alloy for energy conversion.
• Løberg, Monika; Løvvik, Ole Martin; Almeida Carvalho, Patricia; Karlsen, Ole Bjørn & Gunnæs, Anette Eleonora (2019). Phase Transformations within the Cu-Pd-Sn system.
• Løberg, Monika; Pike, Nicholas; Almeida Carvalho, Patricia; Karlsen, Ole Bjørn; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2019). Martensitic-like phase transformations within the Cu-Pd-Sn system.
• Løberg, Monika; Pike, Nicholas; Karlsen, Ole Bjørn; Almeida Carvalho, Patricia; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2019). Characterization of phase transforming, Heusler based (Cu-Pd-Sn), alloys for energy harvesting..
• Strandbakke, Ragnar; Bjørheim, Tor Svendsen; Sørby, Magnus Helgerud; Wachowski, Sebastian Lech; Mielewczyk-Gryn, Aleksandra; Balaguer, Maria; Gunnæs, Anette Eleonora; Almeida Carvalho, Patricia & Norby, Truls Eivind (2019). Hydration and hydrogenation of mixed conducting BaGd1‑xLaxCo2O6‑δ (BGLC).
• Sunding, Martin Fleissner; Løberg, Monika; S. Azar, Amin; Stange, Marit Synnøve Sæverud; Almeida Carvalho, Patricia; Karlsen, Ole Bjørn; Pike, Nicholas; Gunnæs, Anette Eleonora; Diplas, Spyridon & Løvvik, Ole Martin (2019). The Need for a Multi-Technique Approach in the Search for New Phase-Transforming Materials. Vis sammendrag

  Introduction/Purpose Reversible diffusionless first-order phase transformations are a fundamental part of phase change materials and shape memory alloys [1]. Some of these materials even possess useful physical characteristics that show abrupt changes e.g. in their electrical[2] and magnetic [3] polarizations. These phase transformations can be studied using multiple techniques, enabling access to different types of information including length scales and time periods, but how should this characterisation be approached? Methods TEM studies give highly relevant data in this field of research, from detailed crystallographic structures, to relative orientations between grains and phases and to the phase transformation temperature. However, TEM analyses are time consuming and requires small sample sizes and ad hoc preparation. High-throughput measurement techniques are thus required in the search for improved compositions and new materials in order to rapidly assess the properties of many samples or samples with graded composition [4]. Optical methods (for example unpolarised and polarised microscopy and thermal imaging) and electric conductivity measurements can for example be used to map phase transformation temperatures much faster and on much larger areas than traditional TEM techniques. XRD and SEM-EDS-EBSD can then be applied to obtain initial crystallographic and microstructure information on an intermediate size scale, before TEM is applied for the in-depth study of the most relevant compositions. Results We applied this multi-pronged approach in the search for Heusler and half-Heusler alloys with a low temperature martensitic phase transformation and with low thermal hysteresis, with potential applications in waste heat energy harvesting. Conclusions Drawing advantage of the strengths of multiple analysis techniques – with respect to the obtainable information, the sample size and/or the time frame of the analyses – renders the search for new phase change materials more effective. It enables faster identification of potential target compositions and of sample areas optimal for in depth studies. Selected references [1] David Dye, Nature Materials14 (8), 760 (2015). [2] M. M. Vopson, Critical Reviews in Solid State and Materials Sciences40 (4), 223 (2015). [3] L. Huang, D. Y. Cong, L. Ma, Z. H. Nie, Z. L. Wang, H. L. Suo, Y. Ren, and Y. D. Wang, Applied Physics Letters108 (3) (2016). [4] M. L. Green, C. L. Choi, J. R. Hattrick-Simpers, A. M. Joshi, I. Takeuchi, S. C. Barron, E. Campo, T. Chiang, S. Empedocles, J. M. Gregoire, A. G. Kusne, J. Martin, A. Mehta, K. Persson, Z. Trautt, J. Van Duren, and A. Zakutayev, Applied Physics Reviews 4 (1), 011105 (2017).

• de Ruiter, Lisa; Austrheim, Håkon Olaf; Dysthe, Dag Kristian & Gunnæs, Anette Eleonora (2018). Quartz weathering associated with magnesium silicate hydrate cement precipitation.
• de Ruiter, Lisa; Austrheim, Håkon Olaf; Gunnæs, Anette Eleonora & Dysthe, Dag Kristian (2018). Quartz dissolution and M-S-H cement precipitation in a high pH ultramafic system.
• Løberg, Monika; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2018). Energy Conversion using Phase Transforming Materials - the Cu-Pd-Sn system.
• Løberg, Monika; Løvvik, Ole Martin & Gunnæs, Anette Eleonora (2018). Martensitic like phase transformations in the Cu-Pd-Sn system.
• Strandbakke, Ragnar; Gunnæs, Anette Eleonora; Carvalho, Patricia A.; Mielewczyk-Gryn, Aleksandra; Wachowski, Sebastian; Balaguer, Maria; Sørby, Magnus Helgerud & Norby, Truls Eivind (2018). Coupled hydration, cation reorganization and red-ox in MIEC perovskites.
• Berland, Kristian; Eliassen, Simen Nut Hansen; Schrade, Matthias; Tofan, Raluca; Guzik, Matylda Natalia; Gunnæs, Anette Eleonora; Finstad, Terje; Katre, Anikta; Madsen, Georg; Persson, Clas & Løvvik, Ole Martin (2017). Using theory to understand thermoelectric materials.
• Gunnæs, Anette Eleonora (2017). Evaluation of a thermoelectric p-n junction at the macro and nano scale by X-ray and electron probe techniques.
• Gunnæs, Anette Eleonora; Diplas, Spyros & Ulyashin, Alexander G. (2017). A TEM and XPS study of epitaxially grown amorphous hydrogenated silicon in solar cell structures.
• Guzik, Matylda N.; Schrade, Matthias; Tofan, Raluca; Berland, Kristian; Gunnæs, Anette Eleonora; Persson, Clas; Sørby, Magnus Helgerud & Hauback, Bjørn (2017). Structural Investigation of Ti1-xHfxNiySn Half-Heusler Compounds.
• Kepaptsoglou, Despoina Maria; Diplas, Spyridon; Gunnæs, Anette Eleonora & Ulyashin, Alexander (2017). On the evolution of properties of ITO layers deposited on crystalline and amorphous Si upon heat treatments.
• Kepaptsoglou, Despoina Maria; Diplas, Spyridon; Ramasse, Quentin; Gunnæs, Anette Eleonora & Ulyashin, Alexander (2017). A high resolution electron microscopy and spectroscopy study of interfaces in Si-based solar cell heterojunctions.
• Løberg, Monika & Gunnæs, Anette Eleonora (2017). Influence of Mn Stoichiometry on the Structure and Thermoelectric Properties of CaMn(1+y)O(3-d). Vis sammendrag

  The energy consumption of present day society is ever increasing and the sources for more and cleaner energy is sought for. A possible contributor are thermoelectric generators, which convert parts of a heat flux directly into electrical energy. Unfortunately, the efficiency of current generators is too low for large scale commercialization, and new and better materials must be designed. In the present master project, the performance of n-type thermoelectric oxide CaMn(1+y)O(3-d) is attempted improved by creating precipitates within the nano-range. The precipitates could be anticipated to enhance phonon scattering, thereby lowering thermal conductivity and enhance the overall thermoelectric properties of the material. A sample series of CaMn(1+y)O(3-d), with composition y = 0, 0.020 , 0.036, 0.074 and 0.10, has been synthesized by solid state reaction and the microstructure and thermoelectric properties were characterized. Secondary phase, CaMn2O4, precipitates were found from X-ray diffraction and Scanning Electron Microscopy in the size range 5-10 um. Further investigations into the presence of nanoprecipitates were performed by Transmission Electron Microscopy finding no areas enriched in manganese within the CaMnO3 matrix. Electrical resistivity and Seebeck coefficient were measured from room temperature up to 600C finding a resistivity ranging from 20 - 100 mOhm cm and Seebeck coefficient from -300 to -200 uVK-1, showing no trend with manganese content. Thermal conductivity measurements were performed, showing a thermal conductivity between 2.3 - 3.6 Wm-1K-1, however no trend with varying manganese content was observed. Further, the obtained thermoelectric data was compared with samples fabricated using a different synthesis method, yielding similar results and no significant variations was observed. The absence of a Mn-dependency in all transport parameters was carefully confirmed by a thorough investigation of potential experimental influences, like sample porosity, impurity level and measurement uncertainty. Finally, the results are qualitatively rationalized using a simple Callaway model for the thermal conductivity. The concluding remarks are that all manganese excess will manifest as secondary phase CaMn2O4 and no manganese rich precipitates will exist within the CaMnO3 matrix. The variation in manganese content does not influence the thermoelectric properties of CaMn(1+y)O(3-d).

• Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Gunnæs, Anette Eleonora & Prytz, Øystein (2016). The Structure Physics group.
• Gunnæs, Anette Eleonora (2016). Nanoscience with TEM at the Center for Material Science and Nanotechnology/NORTEM, Oslo, Norway.
• Lervik, Adrian; Bjørheim, Tor Svendsen; Nguyen, Phuong Dan; Diplas, Spyridon; Haugsrud, Reidar & Gunnæs, Anette Eleonora (2016). Chemical and Structural Investigations of Grain Boundaries in Y-Doped BaZrO3.
• Lervik, Adrian; Haugsrud, Reidar; Diplas, Spyridon & Gunnæs, Anette Eleonora (2016). Structural- and Compositional Investigations of Grain Boundaries in Y-Doped BaZrO3.
• Schrade, Matthias; Echevarria-Bonet, Cristina; Eliassen, Simen Nut Hansen; Berland, Kristian; Persson, Clas; Tofan, Raluca; Løvvik, Ole Martin; Gunnæs, Anette Eleonora & Finstad, Terje (2016). Thermal Properties of XNiSn(X = Hf, Zr, Ti) half Heusler Alloys.
• Schrade, Matthias; Echevarria-Bonet, Cristina; Guzik, Matylda Natalia; Tofan, Raluca; Gunnæs, Anette Eleonora; Eliassen, Simen Nut Hansen; Berland, Kristian; Persson, Clas; Løvvik, Ole Martin & Finstad, Terje (2016). Thermal properties of XNiSN (X = Ti, Zr, Hf) half Heusler alloys.
• Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud; Hauback, Bjørn Christian; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). Microstructural characterization of spark plasma sintered (X,X’)NiSn half‐Heusler alloys.
• Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud; Hauback, Bjørn Christian; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). The effect of spark plasma sintering on structure and phase stability in half-Heusler thermoelectric alloys.
• Echevarria-Bonet, Cristina; Tofan, Raluca; Schrade, Matthias; Gunnæs, Anette Eleonora; Persson, Clas; Sørby, Magnus Helgerud & Hauback, Bjørn (2015). Enhancement of the thermoelectric properties in nanostructured half-Heusler alloys.
• Fjellvåg, Øystein Slagtern; Sjåstad, Anja Olafsen; Haugsrud, Reidar & Gunnæs, Anette Eleonora (2015). Investigation of Novel Hydride Oxides for Holistic Understanding of Functional Materials.
• Gunnæs, Anette Eleonora (2015). Atomkikking med Norges supermikroskop.
• Lervik, Adrian; Haugsrud, Reidar; Diplas, Spyridon & Gunnæs, Anette Eleonora (2015). A TEM approach to BZY.
• Song, Xin; Valset, Kjetil; Graff, Joachim Seland; Thøgersen, Annett; Gunnæs, Anette Eleonora; Carbalho, Partricia; Luxsacumar, Sivakanesar; Løvvik, Ole Martin; Snyder, G. Jeffrey & Finstad, Terje (2015). Nano Improves Thermoelectric Performance. Vis sammendrag

  The rule of thumb for improving the performance of thermoelectric materials is to reduce the thermal conduction, which attributes to electron transport and phonon transport. Phonons are characterized by different wavelength, Short wavelength phonons are scattered by impurity atoms in alloyed matels, Mid- and Long wavelength phonns are scattered by the iuinterfaces. Nanostructuring can engineer the phonon transport by introduce numerous grain boundaries, thus increasing phonon scattering, further improving thermal resistance. The aim of the present study is the nano-grains of the thermoelectric material ZnSb and the correlation with thermal transport measurements. We explored cryomilling (by ball-milling powders at Cryogenic temperature) as a technique to created nano—powders of ZnSb for pressing into pellets. The effect of cryomilling flowed by hot-pressing of undoped ZnSb was investigated.

• Ulvestad, Asbjørn; Mæhlen, Jan Petter; Andersen, Hanne Flåten; Gunnæs, Anette Eleonora; Prytz, Øystein & Kirkengen, Martin (2015). Characterization of PECVD-Grown a-SiC:H for use as Coating for Silicon Thin Film Anodes in Li-Ion Batteries.
• Løvvik, Ole Martin; Song, Xin; Valset, Kjetil; Flage-Larsen, Espen; Fjeld, Harald; Graff, Joachim Seland; Schrade, Matthias; Karlsen, Ole Bjørn; Larsson, Andreas; Casolo, Simone; Prytz, Øystein; Norby, Truls; Finstad, Terje; Gunnæs, Anette Eleonora & Taftø, Johan (2014). Thermoelectric materials from first principles to final applications: Basic and applied thermoelectrics in Oslo.
• Song, Xin; Persson, Clas; Norby, Truls; Flage-Larsen, Espen; Karlsen, Ole Bjørn; Hansen, Vidar; Gunnæs, Anette Eleonora; Prytz, Øystein; Løvvik, Ole Martin; Finstad, Terje; Valset, Kjetil; Cui, Xuemei; Taftø, Johan; Fjeld, Harald; Hauback, Bjørn & Schrade, Matthias (2014). Conversion of Heat and Energy: Thermoelectrics.
• Song, Xin; Valset, Kjetil; Graff, Joachim Seland; Thøgersen, Annett; Gunnæs, Anette Eleonora; Luxsacumar, Sivakanesar; Løvvik, Ole Martin & Finstad, Terje (2014). Nanostructuring by Cryomilling of Undoped ZnSb.
• Roaldset, Elen; Bering, Dag; Aerts, Maarten & Gunnæs, Anette E. (2013). Kaolinite Group minerals from weathered anorthosite, SW Norway. Berichte derDeutschen Ton- und Tonmineralgruppe e.V..  ISSN 1432-7007.  15, s 27- 27
• Hadidi, Kianoosh; Løvvik, Ole Martin; Norby, Truls Eivind & Gunnæs, Anette Eleonora (2012). Atomistic study of interfaces in the anode electrode of proton conducting fuel cells.
• Holmestad, Randi; Walmsley, John Charles; Prytz, Øystein; Soleim, Bjørn Gunnar; Van Helvoort, Antonius; Olsen, Arne; Gunnæs, Anette Eleonora; Bjørge, Ruben; Sæterli, Ragnhild; Taftø, Johan; Solberg, Jan Ketil; Vullum, Per Erik; Marioara, Calin Daniel; Yu, Yingda; Thørgersen, A.; Rodenwald, M.; Bergius, M. & Lázár, A. (2012). NORTEM – ambitions and plans.
• Qureishy, Thomas; Hansen, Vidar; Karlsen, Ole Bjørn; Gunnæs, Anette Eleonora & Taftø, Johan (2012). Superstructures in Mg2Si1-xSnx.
• Hadidi, Kianoosh; Løvvik, Ole Martin; Norby, Truls & Gunnæs, Anette Eleonora (2010). Atomistic studies of LaNbO4 surfaces and Ni-LaNbO4 interface.
• Hage, Fredrik Sydow; Helgesen, Geir; Gunnæs, Anette Eleonora & Prytz, Øystein (2010). Graphitization of carbon nanocones and nanodiscs.
• Norby, Truls; Fjeld, Harald; Gunnæs, Anette Eleonora; Hadidi, Kianoosh; Kepaptsoglou, Despoina Maria; Løvvik, Ole Martin; Sunding, Martin Fleissner & Toyoura, Kazuaki (2010). Experimental and Computational Studies of Bulk and Interfaces of a Ceramic Proton Conductor at Atomic and Nano Scale.
• stokkan, Therese S.; Gunnæs, Anette Eleonora; Kepaptsoglou, Despoina Maria & Magraso Sola, Anna (2010). Phase segregation in NiO/LaNbO4 composites.
• Sunding, Martin Fleissner; Kepaptsoglou, Despoina Maria; Diplas, Spyridon; Gunnæs, Anette Eleonora & Norby, Truls (2010). Metal-Oxide interfaces in proton conducting fuel cells studied by angle-resolved XPS.
• Fontaine, Marie-Laure; Larring, Yngve; Mei, Sen; Bredesen, Rune; Syvertsen, Guttorm E; Lein, H. L.; Grande, Tor; Sunding, Martin Fleissner; Kepaptsoglou, Despoina Maria; Diplas, Spyridon; Gunnæs, Anette Eleonora; Løvvik, Ole Martin; Olsen, Arne; Magraso Sola, Anna; Skilbred, Anders Werner Bredvei; Haugsrud, Reidar & Norby, Truls (2009). Proton Conducting SOFCs – From Fundamental Understanding to Fuel Cell Stacks.
• Helgesen, Geir; Knudsen, K.D.; Skjeltorp, Arne Torbjørn; Knaapila, M.; Pinheiro, J.P.; Bourgeaux, M.; Heiberg-Andersen, H.; Gunnæs, Anette Eleonora & Prytz, Øystein (2009). The structure and properties of carbon cones.
• Diplas, Spyridon; Løvvik, Ole Martin; Nordmark, Heidi; Kepaptsoglou, Despoina Maria; Graff, Joachim Moe & Gunnæs, Anette Eleonora (2009). Characterisation of transparent conducting oxide (TCO) films and TCO-Si interfaces with XPS, TEM and ab-initio modelling.
• Gunnæs, Anette Eleonora; Prytz, Øystein; Olsen, Arne; Helgesen, Geir & Knudsen, K. D. (2009). Structural study of C-cones and discs by use of analytical TEM.
• Hage, Frefrik Sydow; Gunnæs, Anette Eleonora; Olsen, Arne & Magraso Sola, Anna (2009). A structural study of lanthanum tungstate by CBED.
• Prytz, Øystein; Gunnæs, Anette Eleonora; Breivik, Tallak Harald; Toberer, E. S.; Snyder, G. J. & Taftø, Johan (2009). Nanostructured thermoelectric materials, reduction of thermal conductivity in Zn4Sb3.
• Klinge, Randi Furseth; Dean, MC; Risnes, Steinar; Erambert, Muriel & Gunnæs, Anette Eleonora (2008). Further observations on the microscopic structure and mineral distribution in tooth and periodontal tissues in an australopithecine fossil hominid from Koobi Fora, Kenya.
• Prytz, Øystein; Gunnæs, Anette Eleonora; Breivik, Tallak Harald; Toberer, Eric; Snyder, Jeff & Taftø, Johan (2008). Transmission Electron Microscopy Studies of Nanostructure in ß-Zn4Sb3.
• Prytz, Øystein; Gunnæs, Anette Eleonora; Toberer, Eric; Snyder, Jeff & Taftø, Johan (2008). Transmission electron microscopy search for defects and disorder causing the low thermal conductivity of Zn4Sb3.
• Diplas, Spyridon; Ulyashin, Alexander; Maknys, Kestutis; Gunnæs, Anette Eleonora; Jørgensen, Sissel; Watts, J.F.; Olsen, Arne & Finstad, Terje (2006). On the processing-structure properties of ITO layers deposited on crystalline and amorphous Si.
• Ulyashin, A. G.; Bentzen, Andreas; Diplas, Spyridon; Gunnæs, Anette Eleonora; Olsen, Arne; Svensson, Bengt Gunnar; Suphellen, Aina; Marstein, E. S.; Holt, A; Grambole, Dieter & Sauar, Erik (2006). Hydrogen release and defect formation during heat treatments of SiNx:H/a-Si:H double passivation layer on c-Si substrate.

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