Thermal Expansion of Co2MAl (M = Ti, V, Cr, Mn, Fe, Ni) Band Ferromagnets

Resumo

The thermal expansion coefficient (TEC) of Co₂MAl (M = Ti, V, Cr, Mn, Fe, Ni) band ferromagnets is measured in the temperature interval of 80–900 K. The magnetic-fluctuation contribution α_m, _sf(T) = α_m(T) + α_sf(T) to TEC comprised of negative Stoner α_m(T) and positive spin-fluctuation α_sf(T) contributions is presented. It is assumed that the contribution of α_m(T) component is proportional to the square of spontaneous magnetization. The contribution of α_sf(T) is stipulated by the effects of inducing local magnetic moments by spin fluctuations and is proportional to the Pauli susceptibility.