Band-gap trend of corundum oxides α - <i>M</i>₂O₃ (<i>M</i> = Co, Rh, Ir): An ab initio study

Autor(en)

Xuefen Cai, Su Huai Wei, Peter Deák, Cesare Franchini, Shu Shen Li, Hui Xiong Deng

Abstrakt

In recent years, d6 transition-metal corundum oxides α-M2O3 (M=Co, Rh, Ir) have garnered significant interest due to their notable p-type conductivity; however, their electronic properties remain controversial. In this study, we employ first-principles calculations within different functional levels to systematically investigate the geometry and electronic structure of α-M2O3. Our findings reveal that these oxides have a relatively small difference between the indirect and direct band gap, contradicting previous studies. Additionally, we demonstrate that the band gaps of these oxides are closely associated with the ligand field splitting of the cation M d orbitals and the experimentally observed nonmonotonic trend of the direct band-gap variation can be explained by the orbital-dependent Coulomb and exchange interactions. This study enhances our understanding of how the involvement of d orbitals impacts the band gap of transition-metal oxides.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Beijing Computational Science Research Center, Università di Bologna, Chinese Academy of Sciences (CAS)

Journal

Physical Review B

Band

108

Anzahl der Seiten

6

ISSN

2469-9950

DOI

https://doi.org/10.1103/PhysRevB.108.075137

Publikationsdatum

08-2023

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie, 103043 Computational Physics

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/66708f43-8636-4845-a2bb-68130d830ea4