Annealing effects on the magnetic properties of Nd2Fe17-xGax

Magnetization of Nd2Fe17-xGax, where 0 less than or equal to x less than or equal to 3, has been measured at temperatures between 5 and 300 K and in f ields between 0 and 50 kOe. These samples have the rhombohedral Th2Zn17 str ucture. Magnetization studies at 5 K indicate that the saturation magnetiza tion decreases with increasing Ga concentration while at 300 K it increases for x > 0 reaching a maximum at x = 1, and decreases for x > 1. Samples an nealed for different times are found to have different magnetization for th e same value of x. The low-held magnetization measurements show irreversibl e behavior which is a reflection of hysteretic effects in this system. The peak in the magnetization shifts to higher temperatures upon increasing the Ga amount due to the increase in the Curie temperature. (C) 2000 Published by Elsevier Science B.V. All rights reserved.