Structure, magnetic and magnetocaloric properties of new nanocrystalline (Pr,Dy)Fe9 compounds

Structural, magnetic and magnetocaloric properties for low-cost iron-based new pseudo binary nano-crystalline compounds (Pr,Dy)Fe-9 has been investigated in detail. Four alloys with nominal composition Pr1-xDyxFe9 (x = 0.0625, 0.125, 0.1875, 0.25) were prepared. X-ray diffraction (XRD) coupled to Rietveld analysis with FULLPROF computer code show that the samples crystallize in the hexagonal P6/mmm phase, derived from CaCu5, with the stoichiometry 1/9. The diffraction domain sizes derived from Rietveld analysis are confirmed by transmission electron microscopy. The effect of Dy substitution on the Curie temperature T-C, the saturation magnetization M-s and the magnetocrystalline anisotropy K is studied. The Landau coefficients, the Arrott plots and the magnetic entropy change Delta S-M around the second-order magnetic transition were determined by measuring the magnetic properties. The Magnetocaloric effect properties in these compounds are comparable to that of gadolinium, which is very expensive for domestic use. (C) 2016 Elsevier B.V. All rights reserved.