One-Impurity and Interaction Effects on the Cu:Fe Magnetization

Abstract

The magnetization of very dilute Cu:Fe alloys contains one term proportional to $c$ due to the isolated impurities and another proportional to ${c}^{2}$ which is attributed to nearly magnetic or magnetic pairs. The susceptibility of the isolated iron atoms follows a Curie-Weiss law $C{(T+{T}_{k})}^{\ensuremath{-}1}$ with ${T}_{k}=29$ K well below ${T}_{k}$. The ${c}^{2}$ term which is nearly saturated in 60 kOe at 1.3 K is responsible for the important temperature dependence of the initial susceptibility below ${T}_{k}$.