Work

Thermoelectric phase diagram of the SrTiO3-LaTiO3 solid-solution system through a metal to Mott insulator transition

Year: 2019

Type: article

Abstract: Systematic clarification of thermoelectric properties of a solid-solution system is essentially important, especially if the materials have different crystal and electronic structures. Here, we report the thermoelectric phase diagram of the full-range Sr1 − xLaxTiO3 solid solutions composed of a band insulator SrTiO3 (cubic perovskite) and a Mott insulator LaTiO3 (distorted perovskite), which shows the room temperature thermoelectric power factor changing pattern with the La substitution (x) in the SrTiO3 system. We measured the room temperature thermoelectric properties of Sr1 − xLaxTiO3 (0.01 ≤ x ≤ 1) epitaxial films grown by the pulsed laser deposition and found that there are two thermoelectric phase boundaries at x ∼ 0.5 and x ∼ 0.7 in the Sr1 − xLaxTiO3 system. The former is attributed to the lattice distortion from cubic to orthorhombic variation, whereas the latter is due to the electronic phase transition from metal to Mott insulator. The thermoelectric phase diagram obtained in our study will be fruitful for the future design of n-type thermoelectric materials based on the electron-doped SrTiO3.

Source: Journal of Applied Physics

DOI: 10.1063/1.5100993

Authors: Yuqiao Zhang, Kenyu Sugo, Hai Jun Cho, Hiromichi Ohta

Institutions: Research Institute for Electronic Science, Hokkaido University, Hokkaido University

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Asahi Glass Foundation, Japan Society for the Promotion of Science London, Japan Society for the Promotion of Science

Awards: G1700736949, G7760557641, Thermal conductivity clarification of parallel plate structured material with nanometer sized period - Toward realization of high ZT thermoelectric materials -, Phonon transport properties of thermoelectric oxide thin films and superlattices