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| The Enhanced Magnetic Transition Temperature in Double Perovskites A2FeMoO6(A=Ca, Sr and Ba) : Electron Doping Effects |
| Journal of Magnetics, Volume 10, Number 1, 31 Mar 2005, Pages 10-13 |
J. Kim(Department of Physics, Hankuk University of Foreign Studies), H. M Yang(Department of Physics, Hankuk University of Foreign Studies), B. W. Lee*  (Department of Physics, Hankuk University of Foreign Studies) |
| Abstract |
| We have studied effects of the partial substitution of La3+ for A2+ on the magnetic properties of double perovskites A2FeMoO6 (A=Ca, Sr and Ba). Polycrystalline A2-xLaxFeMoO6(0≤x≤0.2) samples have been prepared by the conventional solid-state reaction in a stream of 5% H2/Ar gas. The x-ray data indicate that A=Ca is monoclinic with the space group P21/n, A=Sr is tetragonal with the space group I4/mmm, and A=Ba is cubic with the space group Fm3m. The substitution of La3+ for A2+ results in a cell volume increase for A=Ca and a cell volume reduction for A=Ba. The decrease of saturation magnetization with increasing x arises from the reduction of magnetic moment associated with the electron doping and the disorder at the Fe and Mo sites. The partial substitution of magnetic La3+ for Ba2+ considerably enhances the Curie temperature Tc from 316 K for x = 0 to 334 K for x = 0.2. This enhancement of Tc with La3+ doping originates from electron doping effects in addition to ionic size ones. |
| Keywords: Double perovskite; Magnetization; Magnetic transition temperature |
| DOI: |
| Full Text: PDF |
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