Magnetocaloric effect in ternary metal phosphides (Fe1-xNix)2P

In this paper, we study the magnetocaloric effect (MCE) (Delta S-m) in the ternary metal phosphides ( Fe1-xNix)(2)P (x = 0.015, 0.025 and 0.1). For this purpose, the magnetization dependence M(H, T) on the temperature T and magnetic field H was measured carefully around the Curie temperature. The transition temperature from ferromagnetic state to paramagnetic state has been evaluated according to M(T) measurements. Magnetic entropy change Delta S-m allowing estimation of the MCE was determined based on thermodynamic Maxwell's relation. The experimental results show that T-c increases in the case of Fe2P from 217K (x = 0) to 313K (x = 0.025). A large magnetic entropy change has been observed. The maximum -Delta S-m of (Fe0.975Ni0.025)(2)P occurring close to T-c = 313K is about 2J/kg K for an applied field change of 1.97 T. The present study suggests that the simple ( Fe1-xNix)(2)P compounds, in particular (Fe0.975Ni0.025)(2)P, are promising candidates as magnetic refrigerant near room temperature. (c) 2007 Elsevier B.V. All rights reserved.