Oguchi’s method and random interaction fields’ method: Investigation of properties of ferromagnetic materials

• Published in: Journal of magnetism and magnetic materials 2019-02, Vol.471, p.501-503
• Main Authors: Belokon, V., Trofimov, A., Dyachenko, O.
• Format: Article
• Language: English
• Subjects: Curie point; Curie temperature; Curing; Ferroelectrics; Ferromagnetic materials; Ferromagnetism; Heat capacity; Heat resistance; Ising model; Magnetic fields; Magnetic phase transitions; Oguchi’s method; Phase transitions; Random field method; Specific heat
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2018.09.065

•The main objective of our work was to demonstrate the possibility of using the association of random interaction fields’ method and Oguchi’s method for the investigation of the magnetic properties of the ferromagnetic material.•Preserving the relative simplicity of the molecular field theory, the random interaction fields’ method combined with Oguchi’s correlations provides a closer estimate of the Curie point and specific heat discontinuity than the Bethe-Peierls and Bragg-Williams methods.•In the Ising model framework, the random interaction fields’ method allows us to determine the distribution function, with parameters calculated by the spin interaction law (or the magnetic moments of particles, clusters, and grains). This approach has advantages over traditional ones since it allows us to connect possible phase transitions with the concentration of exchange-interacting atoms (ions) and calculate critical concentrations. Simultaneously applying cluster methods and the random interaction fields’ method enables a more accurate calculation of the phase transition conditions. The Curie point of a ferromagnetic material is determined in the framework of the Ising model by Oguchi’s method and the random interaction fields’ method. The heat capacity of the system is also investigated. The jump in the heat capacity is calculated at the Curie point. Comparison with known results is made.