1D Spin-Crossover Molecular Chain with Degenerate States

TL;DR

This paper models a one-dimensional spin-crossover molecular chain with degenerate states, connecting it to the Ising model with phononic interactions, and provides exact results for its thermodynamic properties.

Contribution

It establishes a novel connection between the molecular chain and the Ising model with phononic interactions, offering exact analytical results.

Findings

Exact magnetization and correlation functions derived

Identification of two peaks in specific heat capacity

Demonstration of state degeneracy effects on thermal behavior

Abstract

A study of the one-dimensional molecular chain (MC) with two single-particle degenerate states is presented. We establish connection of the MC with the Ising model with phononic interactions and investigate properties of the model using a transfer matrix method. The transfer matrix method offers a promising pathway for simulating such materials properties. The role of degeneracy of states and phononic interaction being made explicit. We analyze regimes of the system and parameters of the occurring crossover. Here, we present exact results for the magnetization per spin, the correlation function and the effective volume of the system. We demonstrate possibility of existence of two peaks in the specific heat capacity thermal behavior.