Spin-Wave Excitations of Amorphous Ferromagnetic Fe₄₀Ni₄₀P₁₄B₆

Abstract

Spin-wave excitations in an amorphous ferromagnetic metal Fe₄₀Ni₄₀P₁₄B₆ were measured by means of a pseudorandom spin modulated time of flight neutron scattering technique. A triple axis time of flight measurements were also made to check the energy resolution in the cross correlated time of flight spectrum. The observed spin-wave dispersion at room temperature is expressed by a quadratic dispersion law E=Δ+Dq² with Δ=0.02±0.09 meV and D=102±8 meV Ų.