Mehdizadeh Dehkordi Arash, Bhattacharya Sriparna, Darroudi Taghi, Zeng Xiaoyu, Alshareef Husam N, Tritt Terry M
Department of Materials Science and Engineering, Clemson University;
Department of Physics and Astronomy, Clemson University.
J Vis Exp. 2015 Aug 15(102):e52869. doi: 10.3791/52869.
We demonstrate a novel synthesis strategy for the preparation of Pr-doped SrTiO3 ceramics via a combination of solid state reaction and spark plasma sintering techniques. Polycrystalline ceramics possessing a unique morphology can be achieved by optimizing the process parameters, particularly spark plasma sintering heating rate. The phase and morphology of the synthesized ceramics were investigated in detail using X-ray diffraction, scanning electron microcopy and energy-dispersive X-ray spectroscopy. It was observed that the grains of these bulk Pr-doped SrTiO3 ceramics were enhanced with Pr-rich grain boundaries. Electronic and thermal transport properties were also investigated as a function of temperature and doping concentration. Such a microstructure was found to give rise to improved thermoelectric properties. Specifically, it resulted in a significant improvement in carrier mobility and the thermoelectric power factor. Simultaneously, it also led to a marked reduction in the thermal conductivity. As a result, a significant improvement (> 30%) in the thermoelectric figure of merit was achieved for the whole temperature range over all previously reported maximum values for SrTiO3-based ceramics. This synthesis demonstrates the steps for the preparation of bulk polycrystalline ceramics of non-uniformly Pr-doped SrTiO3.
我们展示了一种通过固态反应和放电等离子烧结技术相结合来制备Pr掺杂SrTiO₃陶瓷的新型合成策略。通过优化工艺参数，特别是放电等离子烧结加热速率，可以获得具有独特形态的多晶陶瓷。使用X射线衍射、扫描电子显微镜和能量色散X射线光谱对合成陶瓷的相和形态进行了详细研究。观察到这些块状Pr掺杂SrTiO₃陶瓷的晶粒具有富含Pr的晶界。还研究了电子和热传输性质随温度和掺杂浓度的变化。发现这种微观结构可改善热电性能。具体而言，它使载流子迁移率和热电功率因子有了显著提高。同时，它还导致热导率显著降低。结果，在整个温度范围内，相对于所有先前报道的SrTiO₃基陶瓷的最大值，热电优值有了显著提高（>30%）。这种合成方法展示了制备非均匀Pr掺杂SrTiO₃块状多晶陶瓷的步骤。
