Magnetostrictive properties of sputtered binary Tb-Fe and pseudo-binary (Tb-Dy)-Fe alloy films

Magnetostriction (lambda=lambda(parallel to)lambda(perpendicular to)) and other magnetic properties have been investigated for sputtered TbxFe100-x (5 less than or equal to x less than or equal to 60) and (Tb1-yDyy)(42)Fe-58 (0 less than or equal to y less than or equal to 1) alloy systems. These films exhibited an amorphous structure except for x < 7 and 50 < x < 60. In the binary alloy system, the magnetostriction measured at 7 kOe exhibited a maximum of about 450 x 10(-6) at x = 33, corresponding to the composition of TbFe2 Laves phase, while that at 1 kOe exhibited a maximum of about 220 x 10(-6) at x = 42. In the pseudo-binary alloy system, the dependence of lambda on the substitution of Dy was very similar to that of bulk data, implying a similarity of atomic short-range ordering between amorphous and crystalline (Tb-Dy)Fe samples. The substrate temperature during the sputtering much influences upon the lambda measured below 7 kOe. The maximum magnetostriction for both Tb33Fe67 and (Tb0.3Dy0.7)(33)Fe-67 films were obtained at the substrate temperatures of about 400 and 300 degrees C, respectively. A remarkable aging effect was found for the pseudo-binary alloy films and not for the binary alloy films.