Effect of post-annealing on the phase transitions and magnetocaloric properties in bulk Ni44Mn45Sn11 alloy

The effect of low temperature post-annealing on the phase transitions and magnetocaloric properties in bulk Ni44Mn45Sn11 alloy has been investigated. The results indicate that with the increase of annealing temperature, the martensite start temperature decreases rapidly, while the Curie temperature of austenitic phase shows a small decrease. The variations of phase transition temperatures can be attributed to the decrease of atomic order degree characterized by the increases of cell volume. Although the peak value of magnetic entropy change decreases rapidly, the refrigerant capacity shows a slight increase at the annealing temperature <= 300 degrees C due to the wider peaks. (C) 2013 American Institute of Physics