Magnetic and magnetocaloric properties in amorphous CexNi1-x thin films (0.12 ≤ x ≤ 0.43)

Abstract

We investigate the influence of Ce substitution on the magnetic and magnetocaloric properties in CexNi1-x amorphous alloys with x = 0.12, 0.34 and 0.43, synthesized using ultrahigh vacuum evaporation method. The Ni magnetic moment decreases from 0.033µB, 0.0087µB to 0.002µB when Ce content increases from 0.12, 0.34 to 0.43. The same trend was found for Curie temperature TC which decreases from 40 K, 12 K to 2 K. The magnetic behavior and the magnetic transition were analyzed using Landau theory around the transition temperature. The magnetic transition nature is of a second order from ferromagnetic to paramagnetic state. Good agreement was found between the magnetic entropy (−ΔSM) values estimated by Landau theory and those obtained using classical Maxwell relation.