Formation and magnetic properties of new compounds R 3 Fe 29- x Cr x ( R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

Abstract

A systematic investigation of structure and magnetic properties of the new R3Fe29-xCrx compounds (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) has been performed. The Curie temperature of R3Fe29-xCrx increased with increasing atomic number from R = Ce to Gd and decreased from Gd to Dy. The saturation magnetization of R3Fe29-xCrx at 4.2 K decreased gradually with increasing atomic number from R = Y to Dy, except for Ce. The spin reorientations of the easy magnetization direction were observed at around 230 K for Nd3Fe24.5Cr4.5 and 180 K for Tb3Fe28.0Cr1.0, and the magnetohistory effects were observed for Nd3Fe24.5Cr4.5 and Sm3Fe24.0Cr5.0 in a low field of about 0.04 T. First order magnetization process occurs in magnetic field of around 2.3 T at room temperature for Tb3Fe28.0Cr1.0. The saturation magnetization of Y3Fe27.2Cr1.8 at 4.2 K is 52.2 μB/f.u., which corresponds to an average magnetic moment of 1.92 μB per each Fe atom.