中国物理B ›› 2009, Vol. 18 ›› Issue (7): 3035-3039.doi: 10.1088/1674-1056/18/7/070

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Effect of cobalt on the magnetoresistance characteristics of rare-earth doped manganites

江阔1, 宫声凯2   

  1. (1)Department of Defence Science and Technology, Southwest University of Science and Technology, Mianyang 621010, China;Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China; (2)Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
  • 收稿日期:2008-07-28 修回日期:2009-03-02 出版日期:2009-07-20 发布日期:2009-07-20
  • 基金资助:
    Project suppprted by the doctor start-up fund of the Southwest University of Science and Technology of China (Grant No 07ZX0110).

Effect of cobalt on the magnetoresistance characteristics of rare-earth doped manganites

Jiang Kuo(江阔)a)b)† and Gong Sheng-Kai(宫声凯)b)   

  1. a Department of Defence Science and Technology, Southwest University of Science and Technology, Mianyang 621010, China; b Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
  • Received:2008-07-28 Revised:2009-03-02 Online:2009-07-20 Published:2009-07-20
  • Supported by:
    Project suppprted by the doctor start-up fund of the Southwest University of Science and Technology of China (Grant No 07ZX0110).

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摘要： The effect of cobalt-doping on the magnetic, transport and magnetoresistance characteristics of La1-xSrxMnO3 was investigated. The results show that the magnetoelectric property of rare-earth doped manganites is greatly affected by substitution of Co for Mn sites. The Curie temperature as well as the magnetic moment decreases with the increase of doping concentration, and the samples exhibit obvious characteristics of the spin glass state. Moreover, the magnetoresistance is evidently modulated by doping concentration, and the relevant temperature dependence is also suppressed. In addition, low-temperature magnetoresistance is significantly promoted as doping concentration increases, which renders a value of approximately 50% in the temperature range of 5--200~K and varies within 12.5%. It can be attributed to the effect of spin scattering, induced by cobalt doping, on the itinerant electrons of Mn ions, thus introducing a spin-disorder region into the ferromagnetic region of double-exchange interaction between neighbouring Mn3+ and Mn 3+ ions.

Abstract: The effect of cobalt-doping on the magnetic, transport and magnetoresistance characteristics of La1-xSrxMnO3 was investigated. The results show that the magnetoelectric property of rare-earth doped manganites is greatly affected by substitution of Co for Mn sites. The Curie temperature as well as the magnetic moment decreases with the increase of doping concentration, and the samples exhibit obvious characteristics of the spin glass state. Moreover, the magnetoresistance is evidently modulated by doping concentration, and the relevant temperature dependence is also suppressed. In addition, low-temperature magnetoresistance is significantly promoted as doping concentration increases, which renders a value of approximately 50% in the temperature range of 5--200 K and varies within 12.5%. It can be attributed to the effect of spin scattering, induced by cobalt doping, on the itinerant electrons of Mn ions, thus introducing a spin-disorder region into the ferromagnetic region of double-exchange interaction between neighbouring Mn3+ and Mn 3+ ions.

Key words: cobalt-doped La1-xSrxMnO3, spin scattering, magnetoresistance enhancement

中图分类号:  (Magnetic oxides)

  • 75.47.Lx
75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)) 75.30.Cr (Saturation moments and magnetic susceptibilities) 61.72.S- (Impurities in crystals) 75.30.Et (Exchange and superexchange interactions) 75.50.Dd (Nonmetallic ferromagnetic materials)