2017/05/31 by Chor‐Hoi Chan, Chor-Hoi Chan, G. Brown +2 · 9 citations
Materials Science · Mathematics · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Crossover #Ferromagnetism #Ising model #Magnetism in coordination complexes #Mathematics #Metastability #Monte Carlo method #Phase (matter) #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin crossover #Square lattice #Statistical physics #Theoretical and Computational Physics #Tricritical point #cond-mat.mtrl-sci #cond-mat.other #cond-mat.stat-mech #k-nearest neighbors algorithm
paper · pdf · doi:10.1103/physrevb.96.174428
published in Physical review. B./Physical review. B 96(17) (American Physical Society) · 35 pages, 20 figures
openalex publication_date 2017/11/21 · arxiv created 2017/11/30 · arxiv updated 2017/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We present phase diagrams, free-energy landscapes, and order-parameter distributions for a model spin-crossover material with a two-step transition between the high-spin and low-spin states (a square-lattice Ising model with antiferromagnetic-like nearest-neighbor and ferromagnetic-like long-range interactions) [P. A. Rikvold et al., Phys. Rev. B 93, 064109 (2016)]. The results are obtained by a recently introduced, macroscopically constrained Wang-Landau Monte Carlo simulation method [Phys. Rev. E 95, 053302 (2017)]. The method's computational efficiency enables calculation of thermodynamic quantities for a wide range of temperatures, applied fields, and long-range interaction strengths. For long-range interactions of intermediate strength, tricritical points in the phase diagrams are replaced by pairs of critical end points and mean-field critical points that give rise to horn-shaped regions of metastability. The corresponding free-energy landscapes offer insights into the nature of asymmetric, multiple hysteresis loops that have been experimentally observed in spin-crossover materials characterized by competing short-range interactions and long-range elastic interactions.