Conductivity, weak ferromagnetism and charge instability in $\alpha-MnS$ single crystal

TL;DR

This study investigates the electrical, magnetic, and charge properties of $ ext{α-MnS}$ single crystals across a broad temperature range, revealing charge instability, weak ferromagnetism, and the role of holes in conductivity.

Contribution

It provides a comprehensive analysis of $ ext{α-MnS}$'s charge and magnetic behavior using experimental measurements and a tight binding model, highlighting charge instability and orbital interactions.

Findings

Magnetization hysteresis observed at low temperatures.

Charge susceptibility peaks at specific temperatures.

Holes in $t_{2g}$ and $e_g$ bands influence conductivity.

Abstract

The temperature dependence of resistivity, magnetization and electron-spin resonance of the $\alpha- MnS $ single crystal were measured in temperature range of $5 K < T < 550 K$. Magnetization hysteresis in applied magnetic field up to 0.7 T at $T=5 K, 77 K, 300 K$, irreversible temperature behavior of magnetization and resistivity were found . The obtained data were explained in terms of degenerate tight binding model using random phase approximation. The contribution of holes in $t_{2g}$ and $e_g$ bands of manganese ions to the conductivity, optical absorbtion spectra and charge instability in $\alpha -MnS $ were studied. Charge susceptibility maxima resulted from the competition of the on-site Coulomb interaction between the holes in different orbitals and small hybridization of sub-bands were calculated at $T=160 K, 250 K, 475 K$.