Cation order and structural transition in La2MnCoO6

Abstract

The value of TC and the magnetic behavior of La 2MnCoO6 depend on preparation conditions, in particular on the cooling rate after the last calcinations process. The valence state and the degree of order of cobalt and manganese ions vary according. We expose here two samples of La2MnCoO6 sintered by solid state reaction with different cooling rates. The Rietveld refinement of neutron powder diffraction (NPD) data showed that our samples crystallize in a monoclinic structure with symmetry P21/n up room temperature and ferromagnetic transition around 230K. Sample with lower cooling rate presents a saturation magnetization of 5.58μB/f.u. besides the value of 4.41μB/f.u. for that with higher cooling rate.