Mean-field heat capacity of dilute magnetic alloys

TL;DR

This paper derives an asymptotic solution for impurity heat capacity in dilute magnetic alloys, fitting experimental data and accounting for nonlinear concentration dependence, advancing understanding of s-d systems.

Contribution

It introduces a new asymptotic approach to calculate impurity heat capacity, accurately fitting experimental data without scaling and including nonlinear concentration effects.

Findings

Good agreement with experimental data below 1K for CuCr

Accurate modeling of LaCeAl_2 heat capacity

First account of nonlinear impurity concentration dependence

Abstract

Using an asymptotic solution of the M-impurity thermodynamics of a dilute s-d system, the impurity energy and impurity heat capacity DeltaC(T) are derived for dilute magnetic alloys with spin 1/2 and spin 3/2 impurities. The parameters which enter DeltaC are adjusted to fit experimental data on impurity heat capacity of CuCr and LaCeAl_2. Agreement is satisfactory for CuCr, at temperatures below 1K, and good for LaCeAl_2. The magnitude of theoretical DeltaC(T) agrees with experiment and does not require scaling as in previous s-d theories. Nonlinear dependence of DeltaC(T) on impurity concentration has been accounted for the first time.