Structure and magnetic properties of mechanically alloyed SmCo/sub 7/ compound

The relationship between phase transformation and magnetic properties of mechanically alloyed (MA) SmCo/sub 7/ alloys at different annealing temperatures has been studied. The MA alloy is a mixture of an amorphous phase and a TbCu/sub 7/-type phase, and has low coercivity. Upon annealing, the coercivity initially increases with the amount of SmCo/sub 7/ phase. Maximum coercivity of 18 kOe has been obtained on single phase TbCu/sub 7/-type SmCo/sub 7/ compound by annealing at 650/spl deg/C. At higher annealing temperature, coercivity first decreases with the appearance of CaCu/sub 6/-type SmCo/sub 6/ phase and still further with the formation of Th/sub 2/Zn/sub 17/-type Sm/sub 2/Co/sub 17/ phase at 800/spl deg/C.