Hexaborides 10/24/13
AU researchers are studying ceramic thermoelectrics, which can convert waste heat into useable energy.
Improving the thermoelectric performance of ceramic materials will open up many opportunities for high temperature applications inaccessible to more traditional thermoelectrics, as they are comprised of intermetallic materials.
Hexaborides have the thermoelectric properties that may fit the bill.
Doreen Edwards, Professor of Materials Science and Dean of the School, is collaborating with several researchers to investigate these materials. In collaboration with Dr. Olivia Graeve, Associate Professor at UCSD, Edwards& research group is examining the thermoelectric behavior of calcium, barium and strontium hexaborides.
The study is part of a larger project funded by the National Science Foundation and is aimed at exploring scalable manufacturing and the fundamental behavior of nanoscale boride materials. Specifically, hexaborides are interesting for possible energy and gas storage applications.
Graeve, PI for the project, will be making the powders and AU will be testing them. Professors Scott Misture and Yiquan Wu of Alfred University and Victor Vasquez of University of Nevada (Reno) are also working on the project.
Edwards& group is also looking at several oxide systems, including beta-gallium rutile intergrowths and some indium- gallium-tin-oxide materials. Thermoelectrics require a unique combination of high electrical conductivity, high
Seebeck coefficient, and low thermal conductivity.
“Oxides that have high conductivity and hybrid crystal structures are good candidates,” says Edwards, “and we&re looking at ways to improve their efficiency.” For the past few years, Edwards& has been working with TAM Ceramics to measure the high-temperature thermoelectric properties of some of their materials.
Scott Misture, Inaomri Professor, is leading a separate project to investigate the relationship between structure and thermoelectric properties in niobium oxides.
