Induced anisotropy in reentrant Ni77Mn23 studied by transverse ac susceptibility

The transverse ac susceptibility of Ni77Mn23 was measured in a dc field to analyze the field-dependent anisotropy in the mixed spin-glass ferromagnetic state. The results support a picture that the field-induced Dzyaloshinsky- Moriya-type anisotropy field can be elastically rotated by an applied dc field. The uniaxial field and the exchange field of coupling between adjacent domains are also estimated at 4.2 K. The procedure of rotating a dc field in a plane perpendicular to the ac field gave evidence indicating that there is multidomain configuration even in a dc field almost sufficient to saturate magnetization, which affects the rotation of the anisotropy. A plausible picture for motion of the anisotropy is proposed in connection with the domain configuration.