【摘 要】
：
Strontium titanate (SrTiO3) is a thermoelectric material with large Seebeck coefficient that has potential applications in high-temperature power generators.To simultaneously achieve a low thermal conductivity and high electrical conduc-tivity,polycrystal
【机 构】
：
Inner Mongolia Engineering Research Center of Multi-functioanl Copper Based Materials,School of Mate
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Strontium titanate (SrTiO3) is a thermoelectric material with large Seebeck coefficient that has potential applications in high-temperature power generators.To simultaneously achieve a low thermal conductivity and high electrical conduc-tivity,polycrystalline SrTiO3 with a multi-scale architecture was designed by the co-doping with lanthanum,cerium,and niobium.High-quality nano-powders were synthesized via a hydrothermal method.Nano-inclusions and a nano/micro-sized second phase precipitated during sintering to form mosaic crystal-like and epitaxial-like structures,which decreased the thermal conductivity.Substituting trivalent Ce and/or La with divalent Sr and substituting pentavalent Nb with tetrava-lent Ti enhanced the electrical conductivity without decreasing the Seebeck coefficient.By optimizing the dopant type and ratio,a low thermal conductivity of 2.77 W.m-1.K-1 and high PF of 1.1 mW.m-1.K-2 at 1000 K were obtained in the sample co-doped with 5-mol％ La,5-mol％ Ce,and 5-mol％ Nb,which induced a large ZT of 0.38 at 1000 K.
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