UNCONVENTIONAL FERROMAGNETIC AND SPIN-GLASS STATES OF THE REENTRANT SPIN GLASS FE0.7AL0.3

Spin excitations in a single crystal of Fe{sub 0.7}Al {sub 0.3} were investigated over a wide range of energy and reciprocal space with inelastic neutron scattering. In the ferromagnetic phase, propagating spin wave modes become paramagnonlike diffusive modes beyond a critical wave vector {bold q}{sub 0} , indicating substantial disorder in the long-range ordered state. In the spin glass phase, the spin dynamics are strongly q dependent, suggesting remnant short-range spin correlations. {copyright} {ital 1999} {ital The American Physical Society}