Ab initio Studies of the Possible Magnetism in BN Sheet by Non-magnetic Impurities and Vacancies

TL;DR

This study uses first-principles calculations to explore how non-magnetic impurities and vacancies can induce magnetism in BN sheets, revealing potential magnetic properties depending on defect types and concentrations.

Contribution

It provides new insights into defect-induced magnetism in BN sheets, analyzing various impurities and vacancies and their effects on magnetic properties.

Findings

Magnetization energies increase as defect concentrations decrease.

Exchange energies are small but significant in specific defect systems.

Certain impurities and vacancies can induce magnetic moments in BN sheets.

Abstract

We performed first-principles calculations to investigate the possible magnetism induced by the different concentrations of non-magnetic impurities and vacancies in BN sheet. The atoms of Be, B, C, N, O, Al and Si are used to replace either B or N in the systems as impurities. We discussed the changes in density of states as well as the extent of the spatial distributions of the defect states, the possible formation of magnetic moments, the magnitude of the magnetization energies and finally the exchange energies due to the presence of these defects. It is shown that the magnetization energies tend to increase as the concentrations of the defects decreases in most of the defect systems which implies a definite preference of finite magnetic moments. The calculated exchange energies are in general tiny but not completely insignificant for two of the studied defect systems, i.e. one with O impurities for N and the other with B vacancies.