Effects of Processing Strategies and La + Sm Co-Doping on the Thermoelectric Performance of A-Site-Deficient SrTiO3-δ Ceramics

Iyasara, Adindu C.; Lu, Zhilun; Schmidt, Whitney L.; Sinclair, Derek C.; Reaney, Ian M.

Abstract

The effect of calcining in either air (VSTO-A) or 5% H2/N2 (VSTO-H) on the thermoelectric performance of La and Sm co-doped A-site-deficient Sr1-3x/2Lax/2Smx/2TiO3-δ ceramics is reported. All calcined powders were sintered 6 h in 5% H2/N2 at 1773 K to ≥96% relative density. All peaks in X-ray diffraction patterns indexed as a cubic perovskite phase. Scanning electron microscopy revealed grain sizes ~14 and ~10 μm for VSTO-A and VSTO-H ceramics, respectively. x = 0.30 showed the lowest k (2.99 W/m.K at 973 K) for VSTO-A, whereas x = 0.20 had the lowest (2.67 W/m. K at 973 K) for the VSTO-H ceramics. x = 0.30 VSTO-A showed a thermoelectric figure of merit, ZT = 0.25 (at 973 K), whereas the maximum ZT = 0.30 (at 973 K) was achieved for x = 0.20 VSTO-H ceramics, demonstrating that thermoelectric properties are optimized when all processing is carried out in 5% H2/N2.

Citation

Iyasara, A. C., Lu, Z., Schmidt, W. L., Sinclair, D. C., & Reaney, I. M. (2022). Effects of Processing Strategies and La + Sm Co-Doping on the Thermoelectric Performance of A-Site-Deficient SrTiO3-δ Ceramics. Crystals, 12(11), Article 1622. https://doi.org/10.3390/cryst12111622

• Journal Article Type: Article
• Acceptance Date: Nov 7, 2022
• Online Publication Date: Nov 12, 2022
• Publication Date: Nov 12, 2022
• Deposit Date: Nov 12, 2022
• Publicly Available Date: Nov 14, 2022
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 11
• Article Number: 1622
• DOI: https://doi.org/10.3390/cryst12111622
• Keywords: thermoelectrics; solid-state reaction; particle size; grain structure; thermal conductivity
• Public URL: http://researchrepository.napier.ac.uk/Output/2954767