Density-Driven Resistance Response in $MnS_{2}$: Theory

TL;DR

This paper presents a theoretical analysis of a colossal insulator-to-metal transition in MnS2, attributing it to electron migration from Mn ions to ligand states, supported by a toy model that matches experimental resistivity data.

Contribution

It introduces a simple statistical model to explain the insulator-metal transition in MnS2, emphasizing electron migration over band crossing as the primary mechanism.

Findings

Transition driven by electron migration from Mn to ligand states

Model's resistivity aligns with experimental data

Supports the ligand state migration hypothesis

Abstract

A colossal insulator-to-metal transition in high-spin pyrite phase of $MnS_{2}$ has been experimentally observed \cite{colomns2}. There are two possibilities behind this colossal insulator-to-metal transition: (1) migration of $Mn$ electrons to unoccupied $S^{2-}_{2}$ antibonding states under pressure which leads to conducting ligand states and hence metallic transition, and (2) possibility of band crossing transition. We have analyzed this experimental obervation theoretically using a toy statistical model and found that the transition is due to the migration of electrons from the transition metal ions to the ligand sites (i.e. the possibility (1)). The calculated resistivity compares well with the experimental data within the fitting parameters of the model.