Multiferroic phase transitions in manganites RMnO_3:A two-orbital double exchange simulation  

作　　者：陶永梅 林林 董帅 刘俊明 

机构地区：[1]Laboratory of Solid State Microstructures,Nanjing University [2]Jiangsu Laboratory of Advanced Functional Materials,Changshu Institute of Technology

出　　处：《Chinese Physics B》2012年第10期456-461,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 51031004,11004027,and 11074113);the National Basic Research Program of China (Grant Nos. 2011CB922101 and 2009CB929501);the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions,China

摘　　要：The semi-quantum two-orbital exchange model is used to investigate the effect of small rare-earth ion substitution on orthorhombic RMnO 3 with A-type antiferromagnetic order,using the Monte Carlo algorithm,exact diagonalization,and zero-temperature optimization approaches.It is revealed that the substitution results in a rich multiferroic phase diagram where the coexisting A-type antiferromagnetic phase and spiral spin phase,pure spiral spin phase,coexisting spiral spin phase,the E-type antiferromagnetic phase,and the pure E-type antiferromagnetic phase emerge in sequence.The multiferroic phase transitions modulate substantially the electric polarization,which is consistent qualitatively with recent experiments.The semi-quantum two-orbital exchange model is used to investigate the effect of small rare-earth ion substitution on orthorhombic RMnO 3 with A-type antiferromagnetic order,using the Monte Carlo algorithm,exact diagonalization,and zero-temperature optimization approaches.It is revealed that the substitution results in a rich multiferroic phase diagram where the coexisting A-type antiferromagnetic phase and spiral spin phase,pure spiral spin phase,coexisting spiral spin phase,the E-type antiferromagnetic phase,and the pure E-type antiferromagnetic phase emerge in sequence.The multiferroic phase transitions modulate substantially the electric polarization,which is consistent qualitatively with recent experiments.

关 键 词：multiferroic phase R-site doping two-orbital exchange model 

分 类 号：O469[理学—凝聚态物理]