• Random transverse single-ion anisotropies in the mixed spin-1 and spin-1/2 Blume–Capel quantum model: Mean-field theory calculations

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/096/0025

    • Keywords

       

      Blume–Capel quantum model; mixed spin-1 and spin-1/2; random transverse crystal field; compensation temperature; hysteresis loops.

    • Abstract

       

      We have used mean-field theory based on the Bogoliubov inequality for the free energy to study the effects of random transverse single-ion anisotropies and magnetic field on the mixed spin-1 and spin-1/2 Blume–Capel quantum model with the coordination number z = 3. The interactions of the transverse crystal fields Dx and Dy act only on the spin-1 sites and are randomly active with probability p and q and inactive with probability 1−p and 1−,q respectively. The thermal behaviours of the order parameters are studied to determine the nature of phase transitions and to calculate the phase diagrams on the ($\varphi$x = Dx/Jz, k$_B$T/J ), (p, k$_B$T/J) and (q, k$_B$T/J) planes. It is found that the model exhibits only second-order phase transitions. The compensation temperatures are also observed and their lines, T$_{comp}$-lines, are depicted on the ($\varphi$x ,k$_B$T/J) planes. The hysteresis loops are obtained by introducing an external magnetic field on the system which reveals that the coercive field decreases with temperature and with positive values of $\varphi$x and $\varphi$y . It is also found that remanent magnetisation increases with negative values of $\varphi$x and $\varphi$y.

    • Author Affiliations

       

      G SETO1 R A A YESSOUFOU1 2 A KPADONOU3 E ALBAYRAK4

      1. Institute of Mathematic and Physical Sciences (IMSP), Dangbo, Republic of Benin
      2. Department of Physics, University of Abomey-Calavi, Godomey, Republic of Benin
      3. ENS and Laboratory of Physics and Applications (LPA), d’Abomey, Benin
      4. Department of Physics, Erciyes University, 38039 Kayseri, Turkey
    • Dates

       
  • Pramana – Journal of Physics | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.