Disputation
Due to the ongoing Pandemic, the Disputation will be held digital using Zoom. The Chair of Defence will lead the Disputation and the Defence technician will solve technical issues.
Ex auditorio questions: The Chair of Defence will invite the audience to ex auditorio questions. These can be asked orally, by clicking "Participants - Raise hand" in the Zoom menu. The Zoom-host will grant you to speak in the meeting.
Order the Dissertation as PDF from this email address with the name of the Candidate: a.c.gartner@kjemi.uio.no
Trial lecture
Title:"Electrochromism: principle, chemistry, and application"
Video of the Trial lecture
Conferral summary
Termoelektriske materialer kan konvertere varme direkte til elektrisitet, noe som gjør dem til kandidater for gjenvinning av spillvarme, og derfor bidrar til en mer effektiv energiøkonomi. Denne avhandlingen omhandler forskning på nye termoelektriske materialer fra klassen oksider. Studien gir nye tilnærminger og innsikt i termoelektriske transportfenomener, elektronisk 'band alignment' og termodynamisk kompatibilitet mellom materialer.
Main research findings
Thermoelectric materials are able to directly convert heat into electricity, which makes them predestined candidates for the recuperation of waste heat and contributing to a more efficient energy economy. They hold enormous potential for energy generation, since all thermodynamic processes lose a major portion of their energy in the form of waste heat.
However, conventional thermoelectric materials are often toxic, scarce and/or expensive, and show limited high temperature stability, which currently limits their relevance for large-scale applications. Recently, oxide thermoelectric materials composed of abundant elements have attracted increased interest, as they offer a cheaper, environmental-friendly, and high-temperature stable alternative. Thermoelectric modules are built from pairs of n- and p-type materials, which are often discovered and researched individually, and only later combined to a pair in a module. This often leads to complications, like thermal mismatch or unintended reactions.
In this work the approach was taken to design a compatible pair of new thermoelectric oxides that preclude complications in advance and allow a simpler module architecture. This novel approach is demonstrated on a model pair of iron tungstates. The studies cover thermoelectric properties and transport phenomena of the individual iron tungstates, as well as the thermodynamic compatibility and electronic band alignment between the two materials.