锰系层状钙钛矿复合氧化物设计、制备及磁性能

项目名称： 锰系层状钙钛矿复合氧化物设计、制备及磁性能

项目编号： No.21271139

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 别利剑

作者单位： 天津理工大学

项目金额： 75万元

中文摘要： 项目将按照结构化学原理，设计B位离子由铬、钌、铁、钴或镍等过渡金属离子取代的含锰六方层状钙钛矿化合物，探索合成B位MO6八面体共顶点连接六方层状钙钛矿可能性，通过固相反应或溶剂热等方法合成化合物纯相，研究其磁相关性能，揭示其结构与磁性能之间关系。在前期工作中我们已合成An+1MnnO3n+3(A2O)化合物系列中的3个化合物，但其中组成六方钙钛矿层的MO6八面体均共面连接，本项目将探索合成共顶点连接MO6八面体构成的六方层状钙钛矿化合物，因为共顶点连接过渡金属八面体可能发生长程磁相互作用，表现出磁阻等磁相关独特物理性质。在目标化合物中，六方钙钛矿层被类石墨结构层分隔，可能作为一种研究六方钙钛矿层内金属离子磁相互作用的理想模型，对理解六方钙钛矿层中过渡金属离子的磁相互作用具有重要意义。本项目还将探索解理所合成四方或六方层状钙钛矿层状结构的方法，研究新型复合层片材料制备及磁、电性能。

中文关键词： 钙钛矿；层状结构；氧化物；合成；晶体结构

英文摘要： The aim of this project is to design transition metal M (M= Cr, Ru, Fe, Co or Ni) doped layered-perovskite manganate with corner-sharing MO6 octahedra by tuning the average radii of A or B site according to structure principles, to synthesize pure phase of such manganate by solid state reaction or solvothermal route, and to build up a relationship between the crystal structure and magneto- resistance property or electrical property. In our previous work, three members of a hexagonal layered-structure compound series with formula of An+1MnnO3n+3(A2O) have been synthesized. Unfortunately, the MO6 octahedra in the obtained members are face-shared. As being reported in literatures, long-range super exchange or strongly correlated electron interactions between adjacent B cations may exist in corner-sharing MO6 octahedra, resulting in magneto resistance, that is why corner-sharing MO6 octahedra is wanted for understanding the interaction about the strongly correlated electrons in such new structures. Furthermore, hexagonal perovskite layers in the designed compounds are separated by graphite-like Ca2O layer, which has no magneto interaction inside layer or with the hexagonal perovskite layer, so these compounds are good samples for understanding magneto interaction inside the hexagonal perovskite layer. Layered materi

英文关键词： Perovskite；Layered Structure；Oxide；Synthesis；Crystal Structure