Title: Anisotropic Heisenberg model for the mixed spin-3/2 and spin-1/2 under random crystal field
Author(s):

	D. Sabi Takou (Ecole Polytechnique d'Abomey-Calavi (EPAC-UAC), Department of Fundamentale Sciences, Republic of Benin; Institute of Mathematics and Physical Sciences (IMSP), Republic of Benin),
	M. Karimou (Ecole Nationale Supérieure de Génie Energétique et Procédés (ENSGEP) d'Abomey, Republic of Benin; Institute of Mathematics and Physical Sciences (IMSP), Republic of Benin),
	F. Hontinfinde (Institute of Mathematics and Physical Sciences (IMSP), Republic of Benin; University of Abomey-Calavi, Department of Physics, Republic of Benin),
	E. Albayrak (Erciyes University, Department of Physics, 38039, Kayseri, Turkey)

Thermodynamic properties of the mixed spin-3/2 and spin-1/2 Heisenberg model are examined within the Oguchi approximation in the presence of a random crystal-field (RCF). The RCF is either introduced with probability p or turned off with probability 1-p randomly. The thermal variations of the global magnetization and free energy of the system are investigated to construct the phase diagrams for the classical, quantum and anisotropic cases. Different results revealed that no qualitative changes exist between them. Quantum effects are found to be present and abundant in the quantum model in the negative D -range. This phenomenon has a strong decreasing effect on the critical temperature which becomes much lower than in the classical case. In the presence of an external field, it was observed that coercivity and remanence decrease in a wide range of the absolute temperature.

Key words: exchange anisotropy, Heisenberg model, Oguchi approximation, mixed spin, crystal field

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