La0．45Ca0．55MnO3电荷有序态下的磁电性质和再入型自旋玻璃行为  

Magnetic and Electric Properties and Reentrant Spin-glass Behavior of La_(0.45)Ca_(0.55)MnO_3 in Charge Ordering State

作　　者：王桂英[1,2] 严国清[1,3] 毛强[1,2] 刘宁[1] 彭振生[1] 郭焕银[1] 

机构地区：[1]宿州学院自旋电子与纳米材料安徽省重点实验室培育基地,安徽宿州234000 [2]安徽师范大学物理与电子工程学院,安徽芜湖241000 [3]南京大学固体微结构物理国家重点实验室,江苏南京210093

出　　处：《稀土》2009年第3期10-14,共5页Chinese Rare Earths

基　　金：国家重大研究计划课题(2007CB925001);安徽省教育厅自然科学研究项目资助(2006KJ266B);安徽省教育厅自然科学研究重大项目资助(ZD2007003-1);安徽省教育厅自然科学研究重点项目资助(KJ2008A19ZC)

摘　　要：通过电阻率-温度(temperature dependence of resistivity,ρ-T)曲线、磁化强度-温度(temperature depen-dence of magnetization,M-T)曲线、ESR谱线的测量,研究了La0.45Ca0.55MnO3样品的电磁特性。结果表明,样品在整个测量温区呈现绝缘体行为,输运机制满足可变程跃迁模型。样品存在电荷有序(charge ordering,CO)相,相变温度TCO≈240K,并随温度降低发生顺磁(paramagnetism,PM)→电荷有序(CO)→反铁磁(antiferromagnetism,AFM)变化。值得注意的是,由于样品低温下存在多种复杂的磁相互作用,在40K发生自旋玻璃转变,表现为再入型自旋玻璃行为。Magnetic and electric properties of the sample La0.45Ca0.55MnO3 were studied through the measurements of the temperature dependence of resistivity （0 - T curve）, the temperature dependence of magnetization （ M - T curves） and electron spin reso- nance （ESR） spectra. The results showed that the sample exkibits insulator behavior on the whole measuring temperature range, and the transport mechanism meets the variable range hopping model; charge ordering （CO） phase exists in the sample,the transition temperature T∞≈240K, and the sample exhibits paramagnetism （PM）→charge ordering （CO）→antiferromagnetism （AFM） transition with temperature decreasing. It is worth noticing that, as many kinds of magnetic interactions exist in the sample at low temperature, the sample exhibits spinglass transition at 40K, and shows reentrant spinglass behavior.

关 键 词：电荷有序 可变程跃迁 再入型自旋玻璃 

分 类 号：O482.52[理学—固体物理] O614.33[理学—物理]