Nontrivial phase diagram for an elastic interaction model of spin crossover materials with antiferromagnetic-like short-range interactions

Abstract

We study the phase diagram of an elastic interaction model for spin crossover (SC) materials with antiferromagnetic-like short-range interactions. In this model, the interplay between the short-range interaction and the long-range interaction of elastic origin causes complex phase transitions. For relatively weak elastic interactions, the phase diagram is characterized by tricritical points, at which antiferromagnetic (AF) -like and ferromagnetic (F) -like spinodal lines and a critical line merge. On the other hand, for relatively strong elastic interactions, unusual "horn structures," which are surrounded by the F-like spinodal lines, disorder (D) spinodal lines, and the critical line, are realized at higher temperatures. These structures are similar to those obtained in our previous study [Phys. Rev. B {\bf 93}, 064109 (2016)] of an Ising antiferromagnet with infinite-range ferromagnetic interactions, and we find universal features caused by the interplay between the competing short-range and long-range interactions. The long-range interaction of elastic origin is irrelevant (inessential) for the critical line. In contrast, the AF-like, F-like, and D spinodal lines result from the long-range interaction of elastic origin. This difference causes qualitatively different features of domain formation or nucleation of the new phase: clustering occurs in the former case, while clustering is absent in the latter. Based on the phase diagrams, we discuss the patterns and clustering features of two-step SC transitions, in which the AF-like phase is realized in the intermediate temperature region.

arXiv comment22 pages, 7 figures

References in corpus (16)

• Equilibrium cluster phases and low-density arrested disordered states: The role of short-range attraction and long-range repulsion
• Metastable lifetimes in a kinetic Ising model: Dependence on field and system size
• Simple Two-Dimensional Model for the Elastic Origin of Cooperativity among Spin States of Spin-Crossover Complexes
• Theory of domain patterns in systems with long-range interactions of Coulomb type
• Realization of the mean-field universality class in spin-crossover materials
• Macroscopic nucleation phenomena in continuum media with long-range interactions
• Ising models with long-range dipolar and short-range ferromagnetic interactions
• Effect of the short-range interaction on critical phenomena in elastic interaction systems
• Asymptotic forms and scaling properties of the relaxation time near threshold points in spinodal-type dynamical phase transitions
• Scaling properties of the relaxation time near the mean-field spinodal
• Threshold Phenomena under Photo Excitation of Spin-crossover Materials with Cooperativity due to Elastic Interactions
• Critical temperature and correlation length of an elastic interaction model for spin-crossover materials
• Crossover between a Short-range and a Long-range Ising model
• Equilibrium, Metastability, and Hysteresis in a Model Spin-crossover Material with Nearest-neighbor Antiferromagnetic-like and Long-range Ferromagnetic-like Interactions
• Termination of the Berezinskii-Kosterlitz-Thouless phase with a new critical universality in spin-crossover systems
• Macroscopically constrained Wang-Landau method for systems with multiple order parameters and its application to drawing complex phase diagrams

Cited by in corpus (2)

• Multistability in an unusual phase diagram induced by the competition between antiferromagnetic-like short-range and ferromagnetic-like long-range interactions
• Phase diagrams and free-energy landscapes for model spin-crossover materials with antiferromagnetic-like nearest-neighbor and ferromagnetic-like long-range interactions