第二相金属纳米颗粒掺杂对SrTiO3体系热电性能的调控研究

项目名称： 第二相金属纳米颗粒掺杂对SrTiO3体系热电性能的调控研究

项目编号： No.11204001

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 郑赣鸿

作者单位： 安徽大学

项目金额： 28万元

中文摘要： n型-钙钛矿结构氧化物RxSr1-xTiO3(R=La,Nd等)具有金属导电性,高热电势和大热电功率因子, 作为热电转换材料具有很好的潜在应用价值。然而，该体系较大的晶格热导率导致其热电性能偏低。本项目选取n型-RxSr1-xTiO3为基体相，通过第二相金属纳米颗粒M(M=Ag、Au、Pt)掺杂，合成M/RxSr1-xTiO3纳米复合体系。掺杂的第二相金属纳米颗粒不但加强声子散射降低体系热导率，而且基底相和第二相金属纳米颗粒之间的化学势差异会在两者界面处形成一个界面势垒，该势垒对载流子进行能量过滤和选择性散射而提升热电势，最终达到改善体系热电性能的目的。本项目研究并揭示第二相金属纳米颗粒的种类、颗粒度及含量对体系热电性能的影响，及基体相成分及其载流子浓度变化时，体系热电性能随第二相金属纳米颗粒掺杂的变化规律。揭示复合体系中电声子输运特点，为提高SrTiO3体系氧化物材料的热电性能奠定基础。

中文关键词： 钛酸锶；金属纳米颗粒掺杂；界面势；热电性能；

英文摘要： The RxSr1-xTiO3(R=La,Nd, etc.) oxides with the perovskite structure exhibit n-type metallic conductivity, high Seebeck coefficient, and large power factor, which present great potential applications in thermoelectric conversion devices. However, due to the large lattice thermal conductivity, these oxides exhibit poor thermoelectric performance and thus there is a certain distance away from their practical applications. In the current project, the RxSr1-xTiO3(R=La,Nd, etc)systems are selected as the matrix phase, and the metallic nanoparticles M(=Ag, Au and Pt) as the secondary phase. Via the nanoinclusion of the metallic nanoparticles into the matrix phase, the M/RxSr1-xTiO3 nanocomposites are synthesized. In these nanocomposites, due to the different chemical potential between the RxSr1-xTiO3 matrix phase and the secondary metallic nanoparticles,there will be the interfacial potentials between these two phases.On the one hand, the phonon scattering is enhanced and thus the thermal conductivity is weakened correspondingly. On the other hand, such interfacial potentials cause energy-dependent scattering of electrons, leading to an energy filtering effect, which increases the Seebeck coefficient. As a result, the thermoelectric properties of the RxSr1-xTiO3 systems will be improved. By changing the composition, th

英文关键词： SrTiO3；Metallic nanoinclusion；interfacial；thermoelectric properties；