Structure and magnetic properties of SmCo7-xZrx alloys (x=0-0.8)

The alloys with composition of SmCo7-xZrx(x = 0 - 0.8) were synthesized and characterized in the temperature range of 10-1273 K and at fields up to 5 T. The experimental results show that a small amount of Zr substitution can contribute to a stabilization of the TbCu7 structure, and improve magneto-anisotropy H-a from 90 kOe for x = 0-180 kOe for x = 0.5 at room temperature, and from 140 kOe for x = 0 - 300 kOe for x = 0.5 at 10 K. It is probable that Zr may partly replace a dumbbell of Co atom pair in these alloys. The phase transition between CaCu5, TbCu7, Th2Zn17 and Ce2Ni7 at different heat treatment conditions was also discussed. (C) 1998 American Institute of Physics. [S0021-8979(98)29511-9].