ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Amorphous Fe90−xNixZr10 is a system that exhibits a relatively high degree of magnetic exchange frustration, which becomes stronger as the system approaches the composition of amorphous pure iron. Thus, while samples with moderate amounts of iron (x≥5) are ferromagnetic, the samples with the highest concentration of iron (x≤1) behave like reentrant spin glasses. We have performed a detailed neutron scattering study of the spin-wave excitations in this system for x=1, 5, 10, 20. In all cases, well-defined spin-wave excitations were observed below a transition temperature Tc that decreased from 455 K (for x=20) to 250 K (for x=1). For x=5, 10, 20 the spin-wave stiffness coefficient follows the temperature dependence expected for a conventional ferromagnet but the spin-wave excitations broaden considerably at low temperatures. For x=1 the spin-wave stiffness coefficient softens at low temperatures and an elastic component of the scattering, associated with the development of a spin-glass order parameter, appears below T≈0.28Tc. A coexistence of propagating spin-wave excitations and spin freezing phenomena is observed below this temperature down to T=0.09Tc. These results are discussed in terms of the relevant current theories.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.344618
