La_(1-x)Ca_xCrO_3(x=0～0.335)的反常负磁化行为研究  

Novel Negative Magnetization In La_(1-x)Ca_xCrO_3(x=0～0.335)

作　　者：周茜 宋铭洋 蒲明华 ZHOU Xi;SONG Mingyang;PU Minghua(School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031;Key Laboratory of Maglev Technology and Maglev Train, Southwest J iaotong University, Chengdu 610031)

机构地区：[1]西南交通大学材料科学与工程学院,成都610031 [2]西南交通大学磁浮技术与磁浮列车重点实验室,成都610031

出　　处：《低温物理学报》2018年第2期68-72,共5页Low Temperature Physical Letters

基　　金：中央高校基本科研业务费专项资金(NO.2682015ZT-7)资助的课题

摘　　要：采用溶胶-凝胶法制备了La_(1-x)Ca_xCrO_3(x=0~0.335)多晶样品,并研究其磁性.La_(1-x)Ca_xCrO_3的奈尔温度随掺钙量的增加而降低,在零场冷却模式下外加磁场为10Oe时,La_(1-x)Ca_xCrO_3样品的磁化率-温度曲线均出现负磁化现象,这是该体系中负磁化现象的首次报道.La_(0.665)Ca_(0.335)CrO_3在50K下的磁化率数值远高于其他样品,且其负磁化行为随着外场强度增大而被抑制,说明体系可能同时存在铁磁性相与抗磁性相,外加磁场较低时,铁磁信号被抑制,呈现出温度依赖的负磁化行为;外加磁场较高时,铁磁性信号与负磁性信号叠加,呈现出反铁磁转变特性.La1-xCaxCrO3（x=0～0.335） polycrystalline samples were prepared by sol gel method and their magnetic properties were investigated. The Neel temperature of La1-xCaxCrO3（x=0～0.335）, decreases with the increase of calcium concentration. The magnetic susceptibility-temperature curves of La1-xCa samples exhibit negative magnetization in zero field cooling mode with applied magnetic field of 10 Oe, this is the first report of negative magnetization in La1-xCaxCrO3, Ca, CrOa.The absolute value of magnetic susceptibility of La1-xCaxCrO3 at 50 K is much higher than that of other samples. The negative magnetization of La1-xCaxCrO3 is suppressed with the increasing of the field intensity, indicating that the system may contain both ferromagnetic phase and diamagnetic phase.When the applied magnetic field is low, the ferromagnetic signal is suppressed and the system exhibits a temperaturedependent negative magnetization.When the applied magnetic field is high, the anti-ferromagnetic transition is the superposition of the ferromagnetic signal and the negative magnetic signal.

关 键 词：铬酸镧 负磁化 反铁磁 

分 类 号：O614.331[理学—无机化学]