Critical behaviors of bond and crystal field dilution Blume–Emery–Griffiths model

• Published in: Journal of magnetism and magnetic materials Vol. 308; no. 1; pp. 90 - 96
• Main Authors: Dong, H.P., Yan, S.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2007; Elsevier Science
• Subjects: Blume–Emery–Griffiths model; Bond dilution; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical behavior; Critical-point effects, specific heats, short-range order; Effective field theory; Exact sciences and technology; General theory and models of magnetic ordering; Magnetic properties and materials; Numerical simulation studies; Physics; Random crystal field; 75.10.Dg; 75.60.Ej; Random crystal field; Blume–Emery–Griffiths model; Effective field theory; Bond dilution; 75.40.Cx; Critical behavior; Effective field approximation; Cubic lattices; Phase diagrams; Phase transformations; Hubbard model; Crystal field; Critical phenomena; Random field; Tricritical point; Blume-Emery-Griffiths model
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2006.04.037

The critical behavior of the spin-1 bond and crystal field dilution Blume–Emery–Griffiths model have been investigated on simple-cubic lattice within the framework of the effective field theory. In particular, both bond dilution and random crystal field are considered at the same time. The interplay between bond and crystal field dilution constructs rich and interesting phase diagrams. Significant distinctions are exhibited. When positive ratio α changes in a certain range, there exist double tricritical points in phase-transition lines in T– D plane. Moreover, this first-order phase transition is enlarged with increasing of ratio α at a fixed crystal field dilution concentration, while this first-order phase transition will shrink when bond dilution concentration is fixed. In addition, we observe that there exist two bond percolation thresholds for negative crystal field and α>0 in T– P plane.