Orthorhombic Magnetic Anisotropy of {110} GdBi Garnet Films

Four series of {110} GdBi garnet film bubble memory media with orthorhombic anisotropy were grown on {110} Nd3Ga5O12 garnet substrates. The orthorhombic anisotropy energy differences Ku ([110] to [001]) and Kp ([110] to [110]) were calculated from the anisotropic magnetic field and the 4¿Ms value. Values were thus obtained for parameters A and B in Gyorgy´s two-parameter model. Calculations of the growth-induced component of the Gyorgy parameters A and B as functions of growth temperature showed that, in the fourth series of films, BO¹¹⁰ and BO¹¹¹ were identical. Up to now, BO¹¹⁰ and BO¹¹¹ have the same values only for (YBi)3 (FeGa)5 O12. 3 ¿m-diameter bubble material was obtained using the third series of films.