Magnetic properties of gadolinium-rich alloys

Abstract

The change in the saturated magnetic moment and the depression of ${T}_{c}$ caused by different nonmagnetic solutes in Gd suggest that the basic Ruderman-Kittel-Kasuya-Yosida theory for the $4f$---conduction-electron interaction is not directly applicable to alloys. The saturated moment, a local property, is found to vary linearly with the $\frac{c}{a}$ ratio. Remarkably, no correlation with $\frac{c}{a}$ is found for ${T}_{C}$, a global property; rather, ${T}_{C}$ is found to vary nearly linearly with the residual resistivity. It is shown that the ${T}_{C}$ dependence can be understood by taking into account the decreased $4f\ensuremath{-}4f$ coupling caused by the finite mean free path of the conduction electrons in the alloys.