Neutron-scattering study of the spin dynamics of amorphous invar alloys
Neutron inelastic scattering experiments were used to investigate the spin dynamics of the amorphous rapidly-quenched alloy systems Fe/sub 100-x/B/sub x/ (for x = 14, 18) and Fe/sub 90-x/Ni/sub x/Zr/sub 10/ (for x = 5, 10, 20). At all boron and nickel concentrations x under study these systems exhibit Invar behavior, where the thermal expansion is almost completely canceled by a large positive magnetostriction. The spin-wave energies determined at small wave vectors were well described by a quadratic dispersion relation E = D(T) q/sup 2/ + ..delta.., where D(T) is the stiffness parameter and ..delta.. is a small gap originating primarily from dipole interactions. Extensive analysis of the damping of the spin-wave excitations in Fe/sub 86/B/sub 14/ revealed that the temperature and wave-vector dependence of the spin-wave intrinsic linewidth are in agreement with the prediction of the conventional two-magnon interaction theory of the Heisenberg ferromagnet. Their analysis of the damping of the spin-wave excitations of Fe/sub 85/Ni/sub 5/Zr/sub 10/ has revealed that the linewidth data are in agreement with the wave-vector dependence predicted by the two-magnon interaction theory, although the temperature dependence is weaker than expected.
- Research Organization:
- Maryland Univ., College Park (USA)
- OSTI ID:
- 5524495
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spin-wave excitations in amorphous Fe/sub 78/B/sub 13/Si/sub 9/
Role of the Fe sub-lattice on the Invar anomaly in R{sub 2}Fe{sub 14}B compounds.