Correlation between magnetoresistance and magnetic entropy at first-order and second-order phase transitions in Ni–Mn–In–Si Heusler alloys

A correlation between the magnetic part of the entropy and magnetoresistance has been studied using measurements of the resistivity, magnetoresistance, and magnetization of the Ni$_{50}$Mn$_{35}$In$_{12}$Si$_3$ and Ni$_{50}$Mn$_{35}$In$_{11}$Si$_4$ Heusler alloys. It has been shown that although the variations of the entropy and the magnetoresistance are observed to be maximal within the same temperature intervals in the vicinity of the first-order and second-order phase transitions, there is no universal correlation between these effects.