Year: 2019
Type: article
Abstract: Transition metal oxides are considered promising thermoelectric materials for harvesting high-temperature waste heat due to their chemical and thermal stability, abundance, and low toxicity. Despite their typically strong ionic character, they can exhibit surprisingly high power factors $\ensuremath{\sigma}{S}^{2}$, as in $n$-type ${\mathrm{SrTiO}}_{3}$ for instance. Thus, it is worth examining other transition metal oxides that might equal or even surpass the performances of strontium titanate. This theoretical paper investigates the thermoelectric properties of $n$-type rutile ${\mathrm{TiO}}_{2}$, which is the most stable phase of titanium oxide up to $2000\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. The electronic structure is obtained through density functional theory calculations, while the prominent features of strong electron-phonon interaction and defects states are modeled using a small number of parameters. The thermoelectric transport properties are computed by solving the Boltzmann transport equation with the relaxation time approximation. The theoretical results are compared with a wealth of experimental data from the literature, yielding very good agreements over a wide range of carrier concentrations. This validates the hypothesis of band conduction in rutile ${\mathrm{TiO}}_{2}$ and allows the prediction of the high-temperature thermoelectric properties.
Authors: S. Thébaud, Ch. Adessi, G. Bouzerar
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2974566365