Journal of Inorganic Materials ›› 2018, Vol. 33 ›› Issue (11): 1237-1247.DOI: 10.15541/jim20180047

• Orginal Article • Previous Articles     Next Articles

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

LIU Jiao1, WANG Wen-Qing1,2, WU Hong-Ye1,2, TIAN Ye1, CAO Feng-Ze1, ZHAO Jian-Jun1,2   

  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 Published:2018-11-16 Online: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))

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)

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