Enhancing the thermoelectric properties of Sr_{1- x}Pr_{2 x/3}□ _x/3TiO_{3± δ} through control of crystal structure and microstructure.

ABSTRACT: A-site deficient perovskites are among the most important n-type thermoelectric oxides. Ceramics of Sr_{1- x}Pr_{2 x/3}□ _x/3TiO₃ ( x = 0.1-1.0) were prepared by solid-state reaction at 1700-1723 K using highly reducing atmospheres. Samples with the highest Sr content had a cubic crystal structure [Formula: see text]; incorporating Pr with A-site vacancies led to a reduction in symmetry to tetragonal ( I4/mcm) and then orthorhombic ( Cmmm) crystal structures. HRTEM showed Pr_2/3TiO₃ had a layered structure with alternating fully and partially occupied A-sites and a short-range order along the (100) direction. Electrical conductivity was highest in samples of high symmetry ( x ≤ 0.40), where the microstructures featured co

SUBMITTER: Ekren D 

PROVIDER: S-EPMC6635635 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature