The diatomic molecule with the mixed spin-1/2 and 1 and their interactions on the Bethe lattice

ALBAYRAK E.

Journal of Magnetism and Magnetic Materials, vol.617, 2025 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 617
  • Publication Date: 2025
  • Doi Number: 10.1016/j.jmmm.2025.172817
  • Journal Name: Journal of Magnetism and Magnetic Materials
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: Bethe lattice, Mixed-spin, Molecule, Phase diagram, Recursion relations
  • Erciyes University Affiliated: Yes

Abstract

The Bethe lattice (BL) is constructed by placing diatomic molecules consisting of one spin-1/2 (σ) and one spin-1 (S) atom at each site. In addition to the interactions of each atom inside a molecule, the molecules are also allowed to interact with their nearest neighbors (NN). For this reason, bilinear interaction parameters, either ferromagnetic (FM) or antiferromagnetic (AFM), between the atoms and the crystal field operating only on the spin-1 atoms are considered, both of which determine the type of molecule produced. It may lead to spin-3/2 for σ=1/2 and S=1, spin-1/2 when σ=±1/2 and S=∓1 and spin-1/2 with σ=±1/2 and S=0. After having obtained the formulation of the model in terms of the exact recursion relations (ERR), the thermal variations of magnetizations are studied in depth to obtain the phase diagrams of the model. Different phase regions are observed with the ordered phase (O), either FM or AFM, or disordered phases, full random (FR), alternating random (AR), and paramagnetic (P) which are separated by possible phase lines.