Magnetic and Transport Properties of La_(0.5-x)Nd_xBa_(0.5) CoO_3 Compounds  

作　　者：张汝贞 刘宜华 王成建 黄宝歆 季刚 梅良模 

机构地区：[1]School of Physics and Microelectronics, Shandong University

出　　处：《Journal of Rare Earths》2003年第5期558-562,共5页稀土学报（英文版）

基　　金：ProjectsupportedbytheStateKeyProjectofFundamentalResearch (G19980 613 0 10 )andtheNationalScientificandTechnologicalDepartmentofChina

摘　　要：Substituting effects of Nd for La in La 0.5 Ba 0.5 CoO 3 compounds were studied systematically. The results show that Nd doping does not change the itinerant properties of the Co3d electrons. The molecular magnetic moment of the materials decreases monotonically with increasing Nd dopant. When Nd content x ≥0.45, a magnetic phase separation appears in the materials. When x ≤0.45, the Curie temperature decreases monotonically with increasing Nd dopant. This is due to the size effects of the rare earth ions. The electric resistance measurements show that in the studied temperature range, the conduction of the materials belongs to the thermo diffusion conduction below the Curie temperature, while it belongs to the variable range hopping conduction of polarons over the Curie temperature.Substituting effects of Nd for La in La 0.5 Ba 0.5 CoO 3 compounds were studied systematically. The results show that Nd doping does not change the itinerant properties of the Co3d electrons. The molecular magnetic moment of the materials decreases monotonically with increasing Nd dopant. When Nd content x ≥0.45, a magnetic phase separation appears in the materials. When x ≤0.45, the Curie temperature decreases monotonically with increasing Nd dopant. This is due to the size effects of the rare earth ions. The electric resistance measurements show that in the studied temperature range, the conduction of the materials belongs to the thermo diffusion conduction below the Curie temperature, while it belongs to the variable range hopping conduction of polarons over the Curie temperature.

关 键 词：metal materials La    0.5-  x    Nd    x  Ba    0.5  CoO  3 compounds size effect itinerant electrons charge transfer rare earths 

分 类 号：O614.3[理学—无机化学]