无机材料学报 ›› 2018, Vol. 33 ›› Issue (11): 1237-1247.doi: 10.15541/jim20180047

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Co掺杂钙钛矿锰氧化物La0.8Sr0.2MnO3电磁特性研究

刘娇1(), 王文清1,2, 吴鸿业1,2, 田野1, 曹凤泽1, 赵建军1,2()   

  1. 包头师范学院 1. 物理科学与技术学院
    2. 内蒙古自治区磁学与磁性材料重点实验室 包头 014030
  • 收稿日期:2018-01-29 修回日期:2018-05-23 出版日期:2018-11-16 发布日期:2018-10-20
  • 作者简介:

    作者简介: 刘 娇(1995-), 女, 硕士研究生. E-mail: 907156479@qq.com

  • 基金资助:
    国家自然科学基金(11164019, 51562032, 61565013);内蒙古自治区科学基金(2015MS0109, NJZZ11166, NJZY12202, NJZY16237);包头市科学技术局产学研合作项目(2014X1014-01, 2015Z2011);内蒙古自治区研究生科研创新项目(S201710127(S01))

Electromagnetic Property of Co-doped La0.8Sr0.2MnO3 Perovskite Manganese Oxides

Jiao LIU1(), Wen-Qing WANG1,2, Hong-Ye WU1,2, Ye TIAN1, Feng-Ze CAO1, Jian-Jun ZHAO1,2()   

  1. 1. Department of Physics, Baotou Normal University, Baotou 014030, China
    2. Inner Mongolia Key Laboratory of Magnetism and Magnetic Materials, Baotou Normal University, Baotou 014030, China
  • Received:2018-01-29 Revised:2018-05-23 Online:2018-11-16 Published:2018-10-20
  • About author:LIU Jiao. E-mail: 907156479@qq.com
  • Supported by:
    National Natural Science Foundation of China (11164019, 51562032, 61565013);Inner Mongolia Natural Science Foundation (2015MS0109, NJZZ11166, NJZY12202, NJZY16237);Science and Technology in Baotou Production- Study-Research Cooperation Projects, China (2014X1014-01, 2015Z2011);Inner Mongolia Autonomous Region Graduate Research and Innovation Project (S201710127(S01))

摘要:

采用传统的高温固相反应法制备了La0.8Sr0.2Mn1-xCoxO3(x = 0, 0.1, 0.3)多晶样品。系统研究了Co掺杂量对La0.8Sr0.2MnO3(LSMO)多晶样品的类Griffiths相、磁熵变、临界行为和电输运性质的影响。研究结果表明: 制备的多晶样品均具有菱形对称结构; 三样品在低温磁转变温度(TC2)以上均存在类Griffiths相; La0.8Sr0.2Mn1-xCoxO3(x = 0, 0.1, 0.3)样品外加磁场为7 T的最大磁熵变ΔSmax分别为-2.28、-2.05和-2.75 J/(kg·K), Co元素的掺杂使得ΔSmax先减小后增大; 母相的临界行为与平均场模型拟合得最好, 掺杂后样品的临界行为和3D海森伯模型拟合最好; 母相为半导体材料, Co元素掺杂量达到0.1时在低温磁转变温度(TC2)附近出现金属绝缘体转变; 高温区三样品的导电方式均满足小极化子模型。

关键词: 钙钛矿锰氧化物, 类Griffiths相, 临界指数, 电性

Abstract:

La0.8Sr0.2Mn1-xCoxO3 (x = 0, 0.1, 0.3) samples were prepared via the conventional high-temperature solid-state reaction method. The effects of Co doping on Griffiths phase, magnetic entropy change, critical behavior, and electrical transport properties of La0.8Sr0.2MnO3 (LSMO) polycrystalline samples were systematically investigated. Results show that the prepared polycrystalline samples all have rhombohedral symmetry structures with Griffiths phase above the low temperature magnetic transition temperature (TC2). When magnetic field is applied to the La0.8Sr0.2Mn1-xCoxO3 (x = 0, 0.1, 0.3) samples, the maximum magnetic entropy change ΔSmax for 7 T is -2.88, -2.05, and -2.75 J/(kg·K), respectively. Doping of Co element makes ΔSmax decrease first and then increase. The critical behavior of the parent phase fits best with the mean field model, and that of the sample after doping fits best with the 3D Heisenberg model. The mother phase is a semiconductor material, and the metal insulator transition appears near the low temperature magnetic transition temperature (TC2) when the Co element doping amount reaches 0.1. The conductivity of the three samples in high temperature region satisfies the small polaron model.

Key words: perovskite manganese oxide, Griffiths-like phase, critical exponent, electrical (electrical property)

中图分类号: 

  • TQ174