1. Random transverse single-ion anisotropy in the spin[formula omitted] Blume–Capel quantum model.
- Author
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Salgado, C.M., de Carvalho, N.L., de Arruda, P.H.Z., Godoy, M., de Arruda, A.S., Costabile, Emanuel, and de Sousa, J. Ricardo
- Subjects
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ANISOTROPY , *PHASE diagrams , *PHASE transitions , *MEAN field theory - Abstract
Abstract We have studied the effects of the random transverse single-ion anisotropy in the phase diagram and in the thermodynamic properties of the spin − 1 Blume–Capel quantum model, which has been used the approach the mean-field theory based on the Bogoliubov inequality for the Gibbs free energy. The phase diagrams were obtained in the temperature τ = k B T ∕ z J versus single-ion anisotropy δ x = D x ∕ z J plane for several values of δ y = D y ∕ z J , p and q. The results show that there is a tricritical behavior only in the range of δ y given by − 0. 048 ≤ δ y < 0. 5. This behavior is shown again by the curves of the magnetization m as a function of temperature τ with corresponding values of δ y , p and q. Highlights • Several phase diagrams were obtained for the spin-1 Blume–Capel quantum model. • The influence of the random single-ion anisotropies was examined for the system. • First- and second-order phase transition lines were found. • The tricritical behavior was examined. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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