La空位和Sr离子掺杂对La-Ca-MnO材料磁性能的影响

Effects of La Vacancy and Sr Doping on the Magnetic Property of La-Ca-MnO Material

摘要: 用溶胶-凝胶法制备了La位空位掺杂La_0.7-xCa_0.28Sr_0.02MnO₃(x=0.00~0.10)系列样品和Sr离子掺杂La_0.77-xCa_0.2Sr_xMnO₃(x=0.00~0.10)系列样品,研究了La位空位掺杂和Sr离子掺杂对样品相结构、居里温度和磁熵变的影响。结果表明,两个系列样品都在近室温有较大磁熵变,对于钙钛矿La-Ca-MnO₃型材料,在La位含少量空位的基础上进行Sr离子掺杂,对居里温度和磁熵都有较积极的调节作用。

Abstract: La vacancy doping La_0.7-xCa_0.28Sr_0.02MnO₃ (x=0.00~0.10) samples and Sr ion doping La_0.77-xCa_0.2Sr_xMnO₃ (x=0.00~0.10) samples were prepared by sol-gel method, and the influence of La space vacancy doping and Sr ion doping on the phase structure, Curie temperature and magnetic entropy change were investigated.Results showed that both series of samples have large magnetic entropy changes at near room temperature; that for the perovskite La-Ca-MnO₃ material, doping Sr ion with a small vacancy in the La position has a positive regulating effect on the Curie temperature and magnetic entropy.