Magnetocaloric effect and magnetostriction in a Ni$_{49.3}$Mn$_{40.4}$In$_{10.3}$ Heusler alloy in ac magnetic fields

The magnetocaloric effect (MCE) and the magnetostriction in the Ni$_{49.3}$Mn$_{40.4}$In$_{10.3}$ Heusler alloy have been measured in ac magnetic fields to 8 T. It is shown that the contributions of the magnetic and structural subsystems to MCE have opposite signs; in this case, the contribution of the magnetic subsystem is dominant. The anomalous temperature dependence of the magnetostriction during the magnetostructural phase transition (PT) is explained by competition of the processes of growing austenite phase nuclei and the striction processes in them.