Magnetic Percolation in New Crystalline FCC Fe-Cu Alloys

Abstract

AbstractMagnetic percolation has rarely been realized in Fe-based binary alloys either because Fe does not retain its moment in the dilute limit or because the solubility is too low. By using a vapor quenching method, which in our case is highrate sputtering, we have succeeded in making new metastable crystalline alloys of fcc FexCu1−x which do not appear in the equilibrium phase diagram. These alloys spanning the percolation threshold allow magnetic percolation phenomena on an fcc lattice to be observed by SQUID magnetometry and Mössbauer spectroscopy. Above xc, the magnetic ordering temperature varies as (x−xc)γ with xc = 0.185 and γ = 0.63. Below xc, spin glass ordering has been observed.