First Principles Calculation of Magnetocrystalline Anisotropy Energy of MnBi and MnB_{1-x}Sn_x

TL;DR

This study uses first principles calculations to analyze the magnetocrystalline anisotropy energy of MnBi and MnB_{1-x}Sn_x, revealing how valence electron changes influence magnetic properties.

Contribution

It provides the first principles calculation of Ku for MnBi and explores how substituting Bi with Sn affects magnetic anisotropy.

Findings

Calculated negative Ku for MnBi consistent with experiments

Valence electron variation can switch Ku from negative to positive

Sn substitution in MnBi significantly increases Ku for x > 0.05

Abstract

We calculated the magnetic anisotropy constant Ku of MnBi using a first principles approach, and obtained a negative Ku in agreeable with experimental results. Furthermore, we also found a band filling dependence indicating that a slight decrease in the valence electron number will change Ku from negative to positive. When some of the Bi is replaced with Sn to decrease the valence electron number, the Ku value of MnBi1-xSnx drastically changes to a positive value, Ku~2 MJ/m3, for x > 0.05.