Investigation on the magnetocaloric effect in (Gd,Pr)Al2 solid solutions

• Published in: Journal of magnetism and magnetic materials 2011-03, Vol.323 (6), p.794-798
• Main Authors: de Sousa, V.S.R., Carvalho, A. Magnus G., Plaza, E.J.R., Alho, B.P., Tedesco, J.C.G., Coelho, A.A., de Oliveira, N.A., von Ranke, P.J.
• Format: Article
• Language: English
• Subjects: Anisotropy; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; Ferrimagnetism; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Magnetocaloric effect; Magnetocaloric effect, magnetic cooling; Physics; Rare earth alloy
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2010.10.046

A theoretical and experimental investigation on the magnetocaloric properties of the rare earth pseudo-binary compounds Gd1−nPrnAl2 is presented. The calculated isothermal entropy and adiabatic temperature changes under magnetic field variations from 0 to 2T and from 0 to 5T are in good agreement with the experimental data. For the Pr-concentrations n=0.25, 0.5 and 0.75 the experimental data present an inverse magnetocaloric effect which was theoretically predicted and associated with the competition between the opposite magnetizations of the Gd and Pr sublattices. The two-sublattice Hamiltonian used in the calculations takes into account the crystal field, exchange and Zeeman interactions. ►Ferrimagnetic coupling between Gd and Pr ions. ►Ferrimagnetic coupling leads to an inverse magnetocaloric effect. ►An inversion in the magnetization sublattices is predicted.