Domain structures in polycrystalline Tb_0.27Dy_0.73Fe₂(Terfenol) at bias fields required for optimum magnetomechanical coupling

Abstract

The Bitter colloid technique has been used in an optical study of field-induced domain changes in polycrystalline Tb0.27Dy0.73Fe2 (Terfenol). Stripe-like domains were observed to form in the bias-field region where the magnetomechanical coupling coefficient of the material is known to maximise and a tentative interpretation of these domain patterns is given. A new colloid technique has been developed for studying domains using scanning electron microscopy and micrographs are presented which show some fine domain details which have not previously been observed.