AC susceptibility, XRD and DSC studies of Sm 1− xGd xMn 2Si 2 silicides

Abstract

X-ray powder diffraction, AC susceptibility and differential scanning calorimetry (DSC) studies were performed on the polycrystalline Sm 1− x Gd x Mn 2Si 2 (0⩽ x⩽1) compounds. All compounds investigated crystallize in the body-centered tetragonal ThCr 2Si 2-type structure with the space group I4/mmm. Substitution of Gd for Sm leads to a linear decrease of the lattice constants and the unit cell volume. The lattice constants and the unit cell volume obey Vegard's law. At low temperatures, the rare earth sublattice orders and reconfigures the ordering in the Mn sublattice. The samples with x=0.6 and 0.8 exhibit spin reorientation phenomenon. The Néel temperature T N(Mn) determined by DSC technique and the Curie temperature T C (RE) increase linearly with increasing Gd content x. The results are summarized in the x− T magnetic phase diagram.