A Model of the Normal State Susceptibility and Transport Properties of Ba (Fe1-xCox)2As2: An Explanation of the Increase of Magnetic Susceptibility with Temperature

TL;DR

This paper presents a simple two-band model that explains the temperature-dependent magnetic susceptibility and transport properties of Ba(Fe1-xCox)2As2, capturing key experimental behaviors with minimal parameters.

Contribution

It introduces a minimal three-parameter two-band model that semi-quantitatively reproduces magnetic and transport data of FeAs-based semimetals, explaining the susceptibility increase with temperature.

Findings

Model reproduces temperature dependence of susceptibility

Captures transport properties like Hall coefficient and Seebeck effect

Explains the increase of magnetic susceptibility with temperature

Abstract

A simple two-band model is used to describe the magnitude and temperature dependence of the magnetic susceptibility, Hall coefficient and Seebeck data from undoped and Co doped BaFe2As2. Overlapping rigid parabolic electron and hole bands are considered as a model of the electronic structure of the FeAs-based semimetals. The model has only three parameters: the electron and hole effective masses and the position of the valence band maximum with respect to the conduction band minimum. The model is able to reproduce in a semiquantitative fashion the magnitude and temperature dependence of many of the normal state magnetic and transport data from the FeAs-type materials, including the ubiquitous increase in the magnetic susceptibility with increasing temperature.