Abstract:
We report results of the first studies on the thermoelectric power (TEP) of the magnetic heusler alloy Ni(2.19)Mn(0.81)Ga. We explain the observed temperature dependence of the TEP in terms of the crystal field splitting and compare the observed behavior to that of the stoichiometric system Ni2MnGa. The resistivity as a function of temperature of the two systems serves to define the structural transition temperature T-M, which is the transition from the high-temperature austenitic phase to the low-temperature martensitic phase.The occurrence of the magnetic (Curie-Weiss) and martensitic transitions at almost the same temperature in Ni(2.19)Mn(0.81)Ga has been explained from TEP to be due to changes in the density of states at the Fermi level.
