摘要
用溶胶凝胶法制备La0.67Sr0.33MnO3(LSMO)粉末,并引入第二相MgO在不同的烧结温度下制备了(1-x)LSMO/xMgO铁磁颗粒系统.对样品的结构、电输运性质和磁电阻进行了系统的研究.结果表明:随MgO含量的增加,样品的电阻率增加、绝缘体金属转变向低温移动、低温电阻极小值现象变得更加明显以及样品的磁电阻增强,但当MgO含量增加到0.07以后,样品的绝缘体金属转变温度又重新增加,其磁电阻也几乎不变.运用颗粒之间的磁耦合关系和自旋极化隧穿机理,对实验结果进行了讨论.
A La0.67Sr0.33MnO3(LSMO)/MgO granular composite system was fabricated at different sintering temperature by synthesizing MgO and LSMO nanopowders prepared by the sol-gel method.The structure and electrical transport and magnetoresistance properties of the samples are systematically investigated.The experimental results show that with the increase of MgO content,the sample′s resistivity increases and the insulator-metal transition shifts to the low temperature and the resistance minimum phenomenon in the low...
出处
《中南民族大学学报（自然科学版）》
CAS
2009年第1期26-30,共5页
Journal of South-Central University for Nationalities：Natural Science Edition
基金
国家自然科学基金资助项目(10574049)
关键词
铁磁颗粒系统
绝缘体金属转变
磁电阻
granular system
insulator-metal transition
magnetoresistance
