MAGNETIC AND MAGNETORESTRICTIVE PROPERTIES OF SM1-XDYXFE2 COMPOUNDS AND ITS MOSSBAUER-EFFECT STUDIES

Measurements of x-ray diffraction, magnetization, magnetostriction, an d Mossbauer effect were performed on a series of Sm1-xDyxFe2 samples ( x=0, 0.1, 0.15, 0.25, 0.45, and 0.65). It is shown that the system ret ains the cubic MgCu2 struCtUre over the whole range and the lattice co nstant decreases linearly with increasing x. Results of Mossbauer effe ct study at room temperature show that for a small amount of Dy substi tution for Sm, x<0.15, easy axes of the magnetization keep in the [111 ] direction. For x>0.15, the direction of easy axes rotates gradually from [111] for x=0, and 0.1 to [100] for x=0.45 and 0.65. The concentr ation dependence of the saturation magnetization exhibits a minimum at x=0.30 for 1.5 K and at x=0.45 for room temperature, reflecting the o ccurrence of the compensation of magnetic moments at various Sm/Dy rat ios. For x=0.45 and 0.65, the pinning phenomenon of narrow domain wall s was observed at low temperature. The magnetostriction was found to d ecrease with the increase in the Dy content, as a result of the compen sation of lambda111 in Sm1-xDyxFe2.