Structural, Magnetic, Magnetocaloric and Mossbauer Spectrometry Study of Gd2Fe17-xCux (x=0, 0.5, 1 and 1.5) Compounds

The structure, magnetic and magnetocaloric properties of arc-melted Gd2Fe17-xCux (x=0, 0.5, 1 and 1.5) solid solution have been studied. The Rietveld refinement shows that these compounds crystallize in the rhombohedral Th2Zn17-type structure with the R3m space group, and the substitution of iron by copper leads to a decrease in the unit cell volume. The Curie temperature (TC) of the prepared samples depends on the copper content. The reduction of the ferromagnetic phase transition temperature from 475K (for x=0) to 460K (for x=1.5) is due to the substitution of the magnetic element (Fe) by non-magnetic atoms (Cu). The magnetocaloric effect was determined in the vicinity of the Curie temperature TC. By increasing the Cu content, an increase in the values of magnetic entropy (SM) in a low applied field is observed. The preferred inequivalent crystallographic site of Cu atoms was determined by Mossbauer spectrometry analysis based on the isomer shift parameter correlation with the Wigner-Seitz cell volumes.