Role of defects on the electronic and magnetic properties of CrAs/InAs and CrAs/CdSe half-metallic interfaces

TL;DR

This study investigates how defects affect the electronic and magnetic properties of CrAs/InAs and CrAs/CdSe interfaces, finding that most impurities do not disrupt half-metallicity except for specific void impurities.

Contribution

It provides a detailed analysis of impurity effects at interfaces in multilayer structures, highlighting the robustness of half-metallicity against most defects.

Findings

Most interface impurities do not alter half-metallicity.

Void impurities at certain sites cause loss of half-metallicity.

Interfaces are likely to retain half-metallicity due to high formation energies of voids.

Abstract

We present an extended study of single impurity atoms at the interface between the half-metallic ferromagnetic zinc-blende CrAs compound and the zinc-blende binary InAs and CdSe semiconductors in the form of very thin multilayers. Contrary to the case of impurities in the perfect bulk CrAs studied in [I. Galanakis and S.G. Pouliasis, J. Magn. Magn. Mat. 321 (2009) 1084] defects at the interfaces do not alter in general the half-metallic character of the perfect systems. The only exception are Void impurities at Cr or In(Cd) sites which lead, due to the lower-dimensionality of the interfaces with respect to the bulk CrAs, to a shift of the $p$ bands of the nearest neighboring As(Se) atom to higher energies and thus to the loss of the half-metallicity. But Void impurities are Schottky-type and should exhibit high formation energies and thus we expect the interfaces in the case of thin multilayers to exhibit a robust half-metallic character.