Synthesis of Sr1-xYxTiO3 by the polymerized complex method and hot pressing

The SrTiO₃ and Y-doped SrTiO₃ polycrystalline sintered bodies were synthesized by the polymerized complex (PC) process and the subsequent hot pressing at 1473 K for 1 h or at 1673 K for 2 h in Ar atmosphere. The X-ray diffraction patterns of the SrTiO₃ and Sr_0.9Y_0.1TiO₃ samples synthesized by the PC process and hot pressing at 1473 K showed that these samples were mostly composed of the SrTiO₃ single phase. On the other hand, in the case of Sr_0.8Y_0.2TiO₃ sample, second phase such as Y₂O₃ precipitated detectably in the XRD patterns. The Seebeck coefficient, |S|, and the electrical resistivity of Sr_0.9Y_0.1TiO₃ were lower than those of the SrTiO₃, indicating the increase in carrier concentration. Both samples hot-pressed at 1673 K showed the power factors larger than those of the samples hot-pressed at 1473 K. Even though the Sr_0.9Y_0.1TiO₃ sample hot-pressed at 1673 K showed the thermal conductivity higher than that of the other samples, the largest dimensionless figure of merit was obtained for this sample over the measured temperature range, because of its large power factor.