A位掺杂金属阳离子半径对稀土锰氧化物LaMnO3晶体结构的影响

摘要

采用溶胶-凝胶(sol-gel)法制备了La0.6A0.4MnO3(A代表Cu,Ag,K,Na)多晶样品材料,对其XRD进行了研究.发现:La0.6Cu0.4MnO3;La0.6K0.4MnO3;La0.6Na0.4MnO3均为单相菱面体钙钛矿结构,La0.6Ag0.4MnO3则由菱面体结构的钙钛矿相和立方结构的金属Ag相组成.对LaMnO3母体进行A位掺杂,随着离子半径不同的金属阳离子的掺入,会导致样品产生晶格畸变,从而使样品的晶格常数,晶胞体积发生变化.变化趋势与掺入的金属阳离子半径有关,随着掺杂离子半径的增大,样品的晶格常数,晶胞体积也相应的增大.%La0.6A0.4MnO3( A represents Cu, Ag, K, Na) poly-crystalline manganite powder was synthesized by sol-gel method, their XRD was researched in detail.The result shows that: La0.6Cu0.4MnO3, La0.6 K0.4 MnO3; La0.6Na0.4MnO3 are single-phase rhombohedral perovskite Mine structure, La0.6 Ag0.4 MnO3 has the rhombohedral structure of the perovskite phase and cubic structure of Ag composition.A site doped for LaMnO3, doped with different ionic radius of metal cation will cause the sample to produce lattice distortion, so that the lattice parameters, cell volume changes.The trends are related to the metal cation radius, as the doping ionic radius increases, the lattice parameters, cell volume increases accordingly.