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

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