High-Figure-of-Merit Thermoelectric La-Doped A-Site-Deficient SrTiO3 Ceramics

Lu, Zhilun; Zhang, Huairuo; Lei, Wen; Sinclair, Derek C.; Reaney, Ian M.

Abstract

The structure and thermoelectric (TE) properties of La-doped, A-site-deficient SrTiO3 (Sr1–3x/2LaxTiO3) ceramics sintered in air and N2/5% H2 have been investigated. Air-sintered ceramics with 0.10 ≤ x < 0.30 appear cubic by X-ray diffraction (XRD) but exhibit superstructure consistent with a tetragonal cell (a0a0c–), according to electron diffraction (ED) studies. 0.30 ≤ x < 0.50 have additional short-range A-site vacancy (VA) ordering, and x ≥ 0.50 are orthorhombic with an a–a–c+ tilt system and long-range VA ordering. 0.10 ≤ x ≤ 0.50 reduced in N2/5% H2 are oxygen-deficient and appear cubic in XRD patterns but exhibit superstructure compliant with an a0a0c– tilt system by ED. For x = 0.50, additional short-range VA order is observed, and x > 0.50 are orthorhombic with an a–a–c+ tilt system and long-range VA ordering. x = 0.15 sintered in N2/5% H2 shows the largest dimensionless TE figure-of-merit ZT = 0.41 at 973 K reported for n-type SrTiO3-based ceramics, suggesting that the accommodation of La through formation of (VSr) coupled with reduction in N2/5% H2 represents a new protocol for the development of oxide-based thermoelectrics.

Citation

Lu, Z., Zhang, H., Lei, W., Sinclair, D. C., & Reaney, I. M. (2016). High-Figure-of-Merit Thermoelectric La-Doped A-Site-Deficient SrTiO3 Ceramics. Chemistry of Materials, 28(3), 925-935. https://doi.org/10.1021/acs.chemmater.5b04616

• Journal Article Type: Article
• Acceptance Date: Jan 6, 2016
• Online Publication Date: Jan 21, 2016
• Publication Date: Feb 9, 2016
• Deposit Date: Oct 23, 2021
• Publicly Available Date: Oct 26, 2021
• Journal: Chemistry of Materials
• Print ISSN: 0897-4756
• Electronic ISSN: 1520-5002
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 3
• Pages: 925-935
• DOI: https://doi.org/10.1021/acs.chemmater.5b04616
• Public URL: http://researchrepository.napier.ac.uk/Output/2815446