Half-metallicity and two-dimensional hole gas at the BiFeO₃(001) surface

2022/05/12 by Soumyasree Jena, Jena, Soumyasree, Sanjoy Datta +1
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Multiferroics and related materials #Physics of Superconductivity and Magnetism #Surface and Thin Film Phenomena

paper · pdf · doi:10.48550/arxiv.2205.06201

openalex publication_date 2022/05/12 · openalex created_date 2022/05/22 · openalex updated_date 2026/07/28

Abstract

The electronic structure and thermodynamic stability of tetragonal \rmBiFeO₃(001) surfaces have been investigated using density functional theory. In this work, four different structures having different lattice constants with two possible surface terminations have been studied. We have found that the surface electronic structure and the thermodynamic stability is quite sensitive with respect to the nature of the surface termination. The \rmFeO₂ terminated surface is found to be energetically more stable compared to \rmBiO terminated surface in all the cases. Interestingly, we have found evidences of half-metallicity and spin-polarized two-dimensional hole gas (2DHG) at the one mono-layer thick surface in all the structures. The effect of the surface thickness have been systematically studied. It has been demonstrated that the half-metallic 2DHG survives only in one of the structures for all the thicknesses, incidentally, which is the most thermodynamically stable structure.

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