Magnetoresistive properties of cerium doped La0.7Ca0.3MnO3 manganites
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Dosyalar
Tarih
2016
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier B.V.
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this work, the effect of doping by tetravalent Ce4+on the structural and magnetoresistive properties of La0.7-xCexCa0.3MnO3 polycrystalline manganites is presented. Samples with x=0, 0.1, 0.2 and 0.3 are prepared by solid state reaction method and characterized. For all doping levels, the X ray diffraction (XRD) analysis shows that the doping element is not completely soluble in the manganite. The cell parameters values, which decrease with Ce content, are refined in the orthorhombic system by taking into account the unreacted CeO2 phase. The observation by scanning electron microscopy (SEM) reveals a change in the morphology of the grains and the porosity of the samples by doping. The temperature dependence of magnetization curves shows a transition from paramagnetic to ferromagnetic state in all samples. A decrease of the Curie temperature Tc with doping is revealed. The resistivity of the samples increases with Ce content and shows a clear metal to insulator transition when measured as a function of temperature. The doping also decreases the temperature Tp of this transition, in accordance with the evolution of Tc values. The calculated magnetoresistance (MR) for a magnetic field of 5T increases gradually from 39.52% for x=0 to 66.18% for x=0.3. © 2016 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Doping, Magnetoresistance, Manganites, Resistivity, Structure
Kaynak
Physica B: Condensed Matter
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
492
