Relaxation phenomena in adiabatic temperature changes near magnetostructural transitions in Heusler alloys

The relaxation processes of the adiabatic temperature changes (ΔTad) at the phase transitions in Ni45Mn43CoSn11, Ni50Mn36.5In13.5, and Ni50Mn35In14.25B0.75 Heusler alloys with different magnetic structures have been studied using a direct extraction method in magnetic fields up to 14 T. It has been found that ΔTad exhibits short relaxation times (less than 10−1 (s)) in the vicinity of the second order phase transitions at the Curie temperatures. The relaxation times of the first order martensitic transitions strongly depend on the latent heat of the transition and can be characterized by a logarithmic law