Magnetocaloric effect in exchange-coupled strong/weak/strong ferromagnet stacks

摘要

We study the magnetocaloric effect in layered systems composed of a ferromagnet with a relatively low Curie temperature (T_C), which is sandwiched by stronger ferromagnets and exchange coupled to them across the interfaces. Switching of magnetization in the softer ferromagnetic surrounding in an applied magnetic field (H) of the strength in several tens of oersteds provides the isothermal magnetic entropy change (△s) in the system because of magnetization redistribution in the spacer. Our simulations of these effects we present here reveal the maximal value of △s, obtained at a realistic interfacial exchange constant, which is in quantitative agreement with this quantity observed experimentally in different heterosystems based on the Ni_xCu_(100-x) (x ～ 70 at. %) spacer.