La_(0.67)Ca_(0.33)MnO_3/MgO复合体系的磁化行为  

Magnetotransport Properties of the La_(0.67)Ca_(0.33)MnO_3/MgO Composites

作　　者：任光明[1] 何伟[2] 

机构地区：[1]广东技术师范学院电子与信息学院,广东广州510665 [2]洪湖市第二中学,湖北洪湖433203

出　　处：《长江大学学报（自科版）（上旬）》2008年第4期46-48,共3页JOURNAL OF YANGTZE UNIVERSITY (NATURAL SCIENCE EDITION) SCI ＆ ENG

基　　金：国家自然科学基金项目(10574049)

摘　　要：用溶胶凝胶自蔓延燃烧法和水浴包覆法制备了(1-x)La_(0.67)Ca_(0.33)MnO_3/MgO复合体系,系统研究了该体系的结构、电输运和磁化行为。在磁化强度随温度降低的变化关系中,观察到2个磁转变。对不同MgO含量的复合样品,观察到的第1个磁转变温度都相同,和纯LCMO的居里温度Tc相对应;观察到的第2个磁转变温度和测得的阻温关系中的Tp对应,随MgO含量的增加向低温移动。最后运用铁磁颗粒系统中颗粒之间的磁藕合关系对实验结果进行了讨论。The composites with the nominal composition of(1-x)La_(0.67)Ca_(0.33)MnO_3/MgO were fabricated by the sol-gel method and water bath coring mothod.The sample constrution,electrical transport and magnetization behavior are systematically investigated.A two-step magnetization behavior was observed in the composites.For the samples with different MgO content,the first magnetic transition temperature is identical,which corresponds with the Curie temperature Tc of the pure LCMO;the second magnetic transition temperature corresponds with the insulator-metal transition temperature Tp,which decreases with the increase of MgO content.The experimental results were discussed in terms of magnetic coupling between the neighboring grains in the ferromagnetic grain systems.

关 键 词：La0.67Ca0.33MnO3/MgO 磁化强度 藕合 

分 类 号：O482.5[理学—固体物理] TM271[理学—物理]