Spin glass-ferromagnetic phase transition in amorphous (FexNi1−x)0.75P0.16B0.06Al0.03

Abstract
Inelastic neutron scattering studies have been carried out on the magnetically isotropic amorphous system (FexNi1−x)0.75P0.16B0.06Al0.03 in the concentration range (x≳0.17) where both ferromagnetic and spin‐glass behavior are observed. For x = 0.4, well defined spin waves which obey the customary quadratic dispersion relation E = DQ2 are observed below the Curie temperature (Tc = 365K) and D is found to increase with decreasing temperature as usual. Below ∼80K, however, D begins to decrease with decreasing temperature as the spin‐glass state is approached. Accompanied by this decrease in D is an increase in the spin wave linewidths. Preliminary results for x = 0.3 and x = 0.2 show qualitatively similar behavior.