Structural and magnetic properties of (Sm_0.5Nd_0.5)_2(Fe_(1-x)Co_x)_(17)compounds

摘要

The structure, magnetization, and magnetocrystalline anisotropy were investigated using X-ray diffraction, vi-brating sample magnetometer, and AC susceptibility-meter. It is found that the microstructure of (Sm0.5Nd0.5)2(Fe1-xCox)17alloys is an (Sm,Nd)2(Fe,Co)17 phase with the rhombohedral Th2Zn17-type structure. The Curie temperature Tc increaseswith the Co concentration increasing, and the magnetization first increases as the Co content increases in(Smo.5Ndo.5)2(Fe1-xCox)17 alloys and then decreases slowly. The easy magnetization direction (EMD) of(Sm0.5Nd0.5)2(Fe0.25Co0.75)17 is along the c-axis and a strong enhancement of the crystalline anisotropy energy constant K isproduced by the addition of some Co atoms. The anisotropy energy constant reaches the maximum when x = 0.75 and thendecreases slowly with the Co content further increasing. The (Sm0.5Nd0.5)2(Fe0.25Co0.75)17 compound is an optical candidatefor the new permanent magnet, which possesses a high magnetization, a high Curie temperature, and a large anisotropy.