Effect of progressive substitution of spin-3/2 by spin-7/2 on the magnetocaloric properties of a mixed spin binary alloy system: A Monte Carlo study

Abstract

Using Monte Carlo simulation the concentration dependency of the cooling exponent (n) of a binary alloy AxB1-x mixed spin system (7/2, 3/2) was studied rigorously. For low magnetic field (h) the entropy change (ΔS), excellently follows the relation ΔS∝hn. The exponent n hardly changes with x within the region 0.5 < x < 0.75. But for further increment of x > 0.75, n sharply drops down. The exponent n is strongly affected by the exchange interaction energy (ε). Due to the decrement of the antiferromagnetic interactions n value rapidly decreases. For the increment of x or the number of A(spin-7/2) atom the magnetization M as well as the magnetic entropy change ΔS increases. The phase transition temperature (i.e. Curie temperature) tC linearly decreases for the increase of x.