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Electrical behavior of nano-polycrystalline (La1-yK y)0.7Ba0.3MnO3 manganites

Mazaheri, M ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jmmm.2010.06.003
  3. Publisher: 2010
  4. Abstract:
  5. We present a study of the structural and electrical behavior of nano-polycrystalline mixed barium and alkali substituted lanthanum-based manganite, (La1-yKy)0.7Ba0.3MnO 3 with y=0.00.3. The samples were synthesized by the polymerization complex solgel method. The powder X-ray diffraction (XRD) data of the samples show a single-phase character with R3c space group. The magnetic and electrical transport properties of the nano-polycrystalline samples have been investigated in the temperature range 50300 K and a magnetic field up to 10 kOe. The metalinsulator transition temperature Tp of all the samples decreased with potassium doping, and also, it increased slightly with the application of magnetic field. The low field magnetoresistance, which is absent in the single-crystalline perovskite, was observed and increased with decreasing temperature. Comparing the experimental resistivity data with the theoretical models shows that the high temperature electrical behavior of these samples is in accordance with the adiabatic small polaron-hopping model. In the metal-ferromagnetic region the resistivity is found to be quite well described by ρ=ρ0ρ2T2ρ4.5T4.5
  6. Keywords:
  7. Low field magnetoresistance ; Manganite ; Adiabatic small polaron ; Electrical behaviors ; Electrical transport properties ; Ferromagnetic regions ; High temperature ; Hopping models ; Metal insulator transition temperature ; Polycrystalline ; Polycrystalline samples ; Potassium doping ; Powder X ray diffraction ; Resistivity data ; Single-crystalline ; Sol-gel methods ; Space Groups ; Temperature range ; Theoretical models ; Barium ; Electric properties ; Electric resistance ; Lanthanum ; Lanthanum compounds ; Magnetic field effects ; Magnetic materials ; Magnetoelectronics ; Magnetoresistance ; Manganites ; Oxide minerals ; Perovskite ; Potassium ; Transport properties ; X ray diffraction ; X rays ; Manganese oxide
  8. Source: Journal of Magnetism and Magnetic Materials ; Volume 322, Issue 21 , November , 2010 , Pages 3255-3261 ; 03048853 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0304885310003847