Magnetocaloric effect in ternary metal phosphides (Fe 1− x Ni x ) 2P

• Published in: Journal of magnetism and magnetic materials 2007-09, Vol.316 (2), p.358-360
• Main Authors: Balli, M., Fruchart, D., Gignoux, D., Tobola, J., Hlil, E.K., Wolfers, P., Zach, R.
• Format: Article
• Language: English
• Subjects: Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetic refrigeration; Magnetically ordered materials: other intrinsic properties; Magnetocaloric effect; Magnetocaloric effect, magnetic cooling; Materials Science; Physics; Ternary metal phosphides (Fe 1−xNi x) 2P
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2007.03.018

In this paper, we study the magnetocaloric effect (MCE) (Δ S m) in the ternary metal phosphides (Fe 1− x Ni x ) 2P ( 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 Δ 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 Fe 2P from 217 K ( x=0) to 313 K ( x=0.025). A large magnetic entropy change has been observed. The maximum −Δ S m of (Fe 0.975Ni 0.025) 2P occurring close to T c=313 K is about 2 J/kg K for an applied field change of 1.97 T. The present study suggests that the simple (Fe 1− x Ni x ) 2P compounds, in particular (Fe 0.975Ni 0.025) 2P, are promising candidates as magnetic refrigerant near room temperature.