Diagnosis of transport properties in Ferromagnets

TL;DR

This paper develops a resistivity model incorporating spin-disorder and polaronic effects to analyze charge transport in ferromagnets, successfully matching experimental data for various materials.

Contribution

It introduces a comprehensive resistivity model that accounts for spin and doping effects, providing accurate predictions for ferromagnetic transport properties.

Findings

Predicted $T_{crossover}$ matches experimental values in GaMnAs.

Calculated carrier densities align with experimental data.

Model successfully describes transport in MnGe ferromagnetic semiconductor.

Abstract

The resistivity model as a function of temperature and ionization energy (doping) is derived with further confinements from spin-disorder scattering in ferromagnetic phase. Magnetization and polaronic effects capture the mechanism of both spin independent and spin-assisted charge transport of ferromagnets, including the newly reported Mn$_x$Ge$_{1-x}$ ferromagnetic semiconductor. The computed $T_{crossover}$ below $T_C$ and carrier density in Ga$_{1-x}$Mn$_x$As system are 8-12 K and 10$^{19}$ cm$^{-3}$, remarkably identical with the experimental values of 10-12 K and 10$^{18}-10^{20}$ cm$^{-3}$ respectively. The calculated charge carriers density for Mn$_x$Ge$_{1-x}$ is 10$^{19}$ cm$^{-3}$, which is also in the same order with the experimental values.