Thermal expansion of Co$_{2}Me$Al ($Me$ = Ti, V, Cr, Mn, Fe, Ni) band ferromagnets

The thermal expansion coefficient (TEC) of Co$_{2}Me$Al ($Me$ = Ti, V, Cr, Mn, Fe, Ni) band ferromagnets is measured in the temperature interval of 80–900 K. The magnetic-fluctuation contribution $\alpha_{m,{\operatorname{sf}}}(T)=\alpha_m(T)+\alpha_{\operatorname{sf}}(T)$ to TEC comprised of negative Stoner $\alpha_ m(T)$ and positive spin-fluctuation $\alpha_{\operatorname{sf}}(T)$ contributions is presented. It is assumed that the contribution of $\alpha_m(T)$ component is proportional to the square of spontaneous magnetization. The contribution of $\alpha_{\operatorname{sf}}(T)$ is stipulated by the effects of inducing local magnetic moments by spin fluctuations and is proportional to the Pauli susceptibility.