The magnetic structure of (Fe80-xRux)B20 metallic glasses

Neutron scattering with polarization analysis has been used to examine the spin-dependent absolute neutron cross-section of Fe80B20, Fe70Ru10B20 and Fe62Ru18B20 metallic glasses. Fe80B20 is shown to be a canted ferromagnet with an average canting angle of approximately 49 degrees in a field of 2 T. Contrary to expectations, there is little or no canting in the samples containing ruthenium as proved by the absence of spin-flip scattering. The magnetic structure of Fe62Ru18B20 has been studied as a function of temperature and magnetic field history. When cooled to 4.2 K in zero field the observed scattering is not consistent with the presence of a spin-glass phase. An increase in the projection of the moments in the direction of the applied field was observed when the sample was cooled to 4.2 K in an applied field of 2 T. The results are discussed in the context of current structural models of (Fe80-xRux)B-20 glasses.