Origin of band gaps in 3d perovskite oxides

• DOI: 10.1038/s41467-019-09698-6
• Publication Date: 2019-04-10T10:18:48Z
• Authors: Julien Varignon; Manuel Bibes; Alex Zunger
• Keywords: Condensed Matter - Materials Science; Electronic properties and materials; Strongly Correlated Electrons (cond-mat.str-el); Science; Q; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 02 engineering and technology; 01 natural sciences; Article; Condensed Matter - Strongly Correlated Electrons; Magnetic properties and materials; 0103 physical sciences; [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]; 0210 nano-technology; [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]

Abstract With their broad range of properties, ABO 3 transition metal perovskite oxides have long served as a platform for device applications and testing bed different condensed matter theories. Their insulating character structural distortions are often ascribed to dynamical electronic correlations within universal, symmetry-conserving paradigm. This view restricts predictive theory complex computational schemes, going beyond density functional (DFT). Here, we show that, if one allows symmetry-breaking energy-lowering crystal symmetry reductions instabilities DFT, successfully systematically recovers the trends in observed band gaps, magnetic moments, type crystallographic ground state, bond disproportionation ligand hole effects, Mott vs. charge transfer insulator behaviors, amplitude deformation modes including Jahn-Teller low temperature spin-ordered high disordered paramagnetic phases. We then provide classification four mechanisms gap formation establish DFT reliable base study state properties oxides.