Magnetic Properties of Gd₂Co_17-xSi_xCompounds

Abstract

Effects of substituting small amounts of Si for Co on the structure and magnetic properties of Gd2CO17 compounds were studied by means of x-ray diffraction and magnetization measurements. All samples are of single phase with the rhombohedral Th2Zn17 type structure. The substitution of Si for Co leads to an approximately linear decrease in the unit cell volume. The saturation moment at 1.5 K decreases linearly with increasing Si concentration, being an approximately linear rate of about 4.1 μB per substituted Si. The Curie temperature of Gd2Co17-xSix is found to decrease monotonously from 1213 to 651 K, as x increases from 0 to 3. X-ray diffraction measurements on magnetically aligned powders show that the easy magnetization direction of Gd2Co17-xSix compounds changes from basal plane to c-axis with increasing Si concentration. The samples with x = 2, 3 exhibit a room temperature uniaxial anisotropy.