Effects of Cu substitution on structural and magnetic properties of La0.7Pr0.3Fe11.4Si1.6 compounds

The structure and magnetic properties of the La0.7Pr 0.3Fe11.4-xCuxSi1.6 compounds have been investigated by X-ray diffraction, scanning electron microscopy and magnetisation measurements. Cu substitution for Fe in La0.7Pr 0.3Fe11.4-xCuxSi1.6 (x = 0, 0.06, 0.12, 0.23, 0.34) leads to a reduction in hysteresis loss, a decrease in magnetic entropy change but an increase in Curie temperature (TC). The influences of annealing processes at different temperatures on T C, magnetic hysteresis, and the magnetocaloric effect (MCE) of La0.7Pr0.3Fe11.4Si1.6 are investigated in detail. It has been found that a short-time and high temperature annealing process has benefits for the formation of the NaZn13 types as phase compared to a long-time and low temperature annealing process