Magnetocaloric Effect And Critical Behavior Of Ni7cu3 Alloys

The Ni7Cu3 alloy was prepared by arc-melting. The magnetic and magnetocaloric properties of alloys had been investigated. The Ni7Cu3 alloy was formed in a single phase with Cubic Ni-type crystal structure. The sample undergoes a second order magnetic phase transition from ferromagnetic (FM) to paramagnetic (PM) and its Curie temperature is 293.7 K A maximum values of magnetic entropy change are found to be 1.3, 1.1, 0.8, 0.6 and 0.3 J.kg(-1)K (-1) under 5T, 4T, 3T, 2T and 1T respectively, which are comparable with some ferromagnetic materials, such as Nd(0.9)Dy(0.1)Co(4)A1. The critical behavior around the transition temperature is investigated in detail, using both the standard Kouvel - Fisher procedure as well as the study of the field dependence of the magnetocaloric effect. The values of the exponents beta and gamma are 0.608 and 2.138 respectively, which are large than the value of pure Ni. Results indicate that there are long-range magnetic coupling for Ni7Cu3 alloy.