相分离体系Nd_(0.85)Sr_(0.15)CoO_3的自旋玻璃行为  

Spin Glass Behavior in Phase-Separated Polycrystalline Perovskite Nd_(0.85)Sr_(0.15)CoO_3

作　　者：杨亦云[1,2] 隋郁[2] 

机构地区：[1]安康学院电子与信息工程系,陕西安康725000 [2]哈尔滨工业大学应用物理系凝聚态科学与技术研究中心,黑龙江哈尔滨150001

出　　处：《济南大学学报（自然科学版）》2010年第4期411-413,共3页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金(50672019)

摘　　要：采用固相反应法合成Nd0.85Sr0.15CoO3多晶样品,应用物理性质测试系统对样品进行直流磁化强度、交流磁化率及交换偏置现象的测试,系统研究了Nd0.85Sr0.15CoO3的自旋玻璃行为。直流磁化强度测试结果显示零场冷却热磁曲线在冻结温度出现峰值,交流磁化率的测试可以看出曲线的峰值随着交流磁场的频率发生变化,而且在磁滞回线的测试结果中观察到与测试场有关的交换偏置现象。直流磁化强度、交流磁化率的测试结果表明,在低温时Nd0.85Sr0.15CoO3为自旋玻璃态。交换偏置现象的出现为自旋玻璃区域位于铁磁团簇和非磁区域之间形成二者之间的界面层提供了强有力的证据。上述结果表明自旋玻璃行为导致了Nd0.85Sr0.15CoO3的相分离。The sample was prepared using conventional solid state reaction method.The spin glass behavior of polycrystalline Nd0.85Sr0.15CoO3 sample was systematically investigated in this paper.The dc magnetization,ac susceptibility,exchange bias phenomenon measurements were carried out using the physical properties measurement system of quantum design.The dc magnetization shows a peak at the freezing temperature of spin glass in the zero-field cooled procedures.The peaks of ac susceptibility show obviously frequency dependence.Moreover,we have observed the measured field dependence of exchange bias phenomenon in the Nd0.85Sr0.15CoO3.The result of the dc magnetization and ac susceptibility suggest the spin glass behavior of polyerystalline Nd0.85Sr0.15CoO3 sample at low temperature.Moreover,the unusual exchange bias phenomenon gives strong evidences for the existence of a spin glasslike phase between FM and non-FM regions at low temperature.Therefore,our study confirms that the phase separation in Nd0.85Sr0.15CoO3 originates from the spin glasslike phase at low temperature.

关 键 词：自旋玻璃 相分离 交换偏置现象 

分 类 号：O482.54[一般工业技术—材料科学与工程]