Gd^(3+)掺杂钙钛矿锰氧化物(La_(0.9)Gd_(0.1))_(4/3)Sr_(5/3)Mn_2O_7的磁性和电性研究  

Magnetic and Electric Properties of Perovskite Manganites( La_(0.9)Gd_(0.1))_(4/3)Sr_(5/3)Mn_2O_7 Polycrystalline

作　　者：王志国[1] 向俊尤 万素磊 武柯含 鲁毅[1] 赵建军[1] 

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古包头014030

出　　处：《阴山学刊（自然科学版）》2014年第3期22-25,共4页Yinshan Academic Journal(Natural Science Edition)

摘　　要：采用传统的高温固相反应法,制备钙钛矿锰氧化物(La0.9Gd0.1)4/3Sr5/3Mn2O7多晶样品,通过X射线衍射仪(XRD)、物性测量系统(PPMS)研究了样品的结构、磁性和电性。结果表明:样品为Sr3Ti2O7型四方结构,空间群为I4/mmm;同时,样品出现了含量非常少的杂质相。磁性测量表明:样品经历了铁磁到顺磁的转变,转变温度(T3DC)为75K。通过电性测量发现:T3DC也是金属性到绝缘性的转变温度。当T3DC<T<300K时,样品是以小极化子近邻跳跃的方式导电,说明电子在跃迁的过程中,其周围的极化子随电子一起运动。（La0.9Gd0.1）4/3Sr5/3Mn2O7 polycrystalline sample was prepared by traclmonat sonu state tertt;t method and The structure, magnetic and electrical properties were investigated by measuring the M -T curve and R -T curve. Experimental results suggest the sample＇ structure was Sr3Ti207 type. It transforms from the three -di- mensional long - range ferromagnetic state to the paramagnetic order at T3D/C. In addition, Electrical properties meas- urement showed that insulator- metal transition temperature for（La0.9Gd0.1）4/3Sr5/3Mn2O7 just occurred at TcD. It can be seen from the fitted R -T curves that the electron conducting mechanism in the temperature range of T3D/C 〈 T 〈 300K is in accordance with small polarons hopping conduction, which indicates the surrounding of polaron fol- lows electronic in the process of movement.

关 键 词：钙钛矿锰氧化物 磁性 电性 磁有序转变温度 

分 类 号：O482.52[理学—固体物理] O614.33[理学—物理]