Neutron-depolarization studies on re-entrant spin glass.

Abstract

Neutron-depolarization studies have been performed on ${\mathrm{Fe}}_{0.7}$${\mathrm{Al}}_{0.3}$ and ${\mathrm{Au}}_{0.81}$${\mathrm{Fe}}_{0.19}$ alloys in order to elucidate the inhomogeneous magnetic state associated with the re-entrant spin-glass (RSG) problem. The wavelength-dependent depolarization reveals that the magnetic state of the RSG, as well as the magnetic state before entering the RSG state on ``mesoscopic'' scale, is quite different for those alloys, in contrast to their similarity in low-field magnetization. This study illustrates that wavelength-dependent neutron depolarization provides a unique tool with which to probe the spatial magnetic state on a ``mesoscopic'' scale.