STRUCTURE AND MAGNETIC-PROPERTIES OF MECHANICALLY ALLOYED SMCO7 COMPOUND

The relationship between phase transformation and magnetic properties of mechanically alloyed (MA) SmCo7 alloys at different annealing tempe ratures has been studied. The MA alloy is a mixture of an amorphous ph ase and a TbCu7-type phase, and has low coercivity. Upon annealing, th e coercivity initially increases with the amount of SmCo7 phase. Maxim um coercivity of 16 kOe has been obtained on single phase TbCu7-type S mCo7 compound by annealing at 650 degrees C. At higher annealing tempe rature, coercivity first decreases with the appearance of CaCu5-type S mCo5 phase and still further with the formation of Th2Zn17-type Sm2Co1 7 phase at 800 degrees C.