Random field distributed Heisenberg model on a thin film geometry

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AKINCI Ü.

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, cilt.368, ss.36-43, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 368
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.jmmm.2014.05.018
  • Dergi Adı: JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.36-43
  • Anahtar Kelimeler: Heisenberg thin film, Special point, Random magnetic field, Tricritical behavior, PHASE-DIAGRAMS, MAGNETIC-PROPERTIES, CURIE-TEMPERATURE, ISING-MODEL, CRITICAL-BEHAVIOR, ULTRATHIN FILMS, MONTE-CARLO, FE FILMS, SURFACE, BILAYER
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The effects of the bimodal random field distribution on the thermal and magnetic properties of the Heisenberg thin film have been investigated by making use of a two spin cluster with the decoupling approximation. Particular attention has been devoted to the obtaining of phase diagrams and magnetization behaviors. The physical behaviors of special as well as tricritical points are discussed for a wide range of selected Hamiltonian parameters. For example, it is found that when the strength of a magnetic field increases, the locations of the special point (which is the ratio of the surface exchange interaction and the exchange interaction of the inner layers that makes the critical temperature of the film independent of the thickness) in the related plane decrease. Moreover, tricritical behavior has been obtained for higher values of the magnetic field, and influences of the varying Hamiltonian parameters on its behavior have been elucidated in detail in order to have a better understanding of the mechanism underlying the considered system. (C) 2014 Elsevier B.V. All rights reserved