Ca掺杂双钙钛矿锰氧化物La_2NiMnO_6的物性研究  

Physical properties of Ca-doped double perovskite La_2NiMnO_6

作　　者：王婷[1] 吴鸿业[1,2] 邢茹[1,2] 孙运斌[1,2] 徐宝[1,2] 李晓欣 赵建军[1,2] WANG Ting;WU Hongye;XING Ru;SUN Yunbin;XU Bao;LI Xiaoxin;ZHAO Jianjun(Department of Physics,Baotou Normal University,Baotou 014030,China;Inner Mongolia Key Laboratory of Magnetism and Magnetic Materials,Baotou 014030,China)

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古包头014030 [2]包头师范学院磁学与磁性材料内蒙古自治区高校重点实验室,内蒙古包头014030

出　　处：《功能材料》2019年第4期4023-4029,共7页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(11164019;51562032;61565013);内蒙古自治区科学基金资助项目(2015MS0109);内蒙高校科学研究基金资助项目(NJZZ11166;NJZY12202;NJZY16237);包头市科学技术局产学研合作资助项目(2014X1014-01;2015Z2011);内蒙古自治区研究生科研创新资助项目(S201710127(S01))

摘　　要：通过磁化强度随温度变化曲线(M-T)和等温磁化曲线(M-H)可判定随着Ca的掺杂,系统的铁磁性减弱、反铁磁性增强;两样品的磁滞回线和2 K下磁滞回线的放大图可以说明Ca的掺杂对系统反位无序度的影响不大,但会导致系统的反相边界增加,反铁磁耦合增强;磁化率倒数随温度变化曲线χ^(-1)-T向上背离C-W定律,掺Ca后向上背离更明显,说明Ca掺杂增强了长程铁磁有序;最后我们讨论了系统磁熵和电性变化,同时阐述了Ca的掺杂使系统经历了弱一级相变。From temperature dependence of magnetization in a magnetic field of 5mT(M-T)and field-dependent magnetization near Curie-temperature(M-H)for La2-x Cax NiMnO6(x=0,0.1),it can be determined that with the doping of Ca,the ferromagnetism of the system was weakened and the antiferromagnetism was enhanced.The Hysteresis loops and the enlarged view of the low-field hysteresis loops at 2 K under the FC process with a cooling field of1 T for La2-x Cax NiMnO6(x=0,0.1)indicated that the doping of Ca had little effect on the disorder degree of the samples,but Ca-doped could increase the anti-phase boundaries and antiferromagnetic coupling of the samples.Temperature dependent inverse magnetic susceptibility(χ^-1)under 5 mT for La2-x-Cax NiMnO6(x=0,0.1)showed upward deviation from CW law.With Ca-doping,the degree of deviation was more obvious,indicating that Ca-doping enhanced long-range ferromagnetic order.Finally,the magnetic entropy of the samples was discussed and it could be explained that Ca-doping made the samples experienced a weak first-order phase change.

关 键 词：双钙钛矿 反位无序度 反相边界 反铁磁耦合 弱一级相变 

分 类 号：O469[理学—凝聚态物理]