Ligand hole driven metal-insulator transition in a prototypical transition metal double perovskite oxide Ca$_2$FeMnO$_6$
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2023
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866917604065542144 |
|---|---|
| author | Sarkar, Arindam Banerjee, Hrishit Das, Debashish Singh, Prashant Alam, Aftab |
| author_facet | Sarkar, Arindam Banerjee, Hrishit Das, Debashish Singh, Prashant Alam, Aftab |
| contents | Ca$_2$FeMnO$_6$ (CFMO) double perovskite was studied using first principles density functional theory and tight-binding (TB) Hamiltonian modeling using extended Hubbard model. We have shown by electronic structure analysis that charge- and magnetic-ordering are driven by charge disproportionation at low temperature caused by partial localization of O-$2p$ ligand holes at alternate Fe sites that creates Jahn-Teller distortion, which leads to metal to insulator transition (MIT) in CFMO. Our results suggests MIT was triggered by negative charge-transfer energy of self-hole doping, responsible for symmetry lowering transitions. Notably, the band-gap was found to fundamentally controlled by the strength of the charge-transfer energy, and not by the Mott-Hubbard interactions, which can be modeled by composition, pressure or stoichiometry modulations. The fundamental insights presented in this work will help understand similar physics and mechanisms in other class of perovskites and correlated metals. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2302_01545 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Ligand hole driven metal-insulator transition in a prototypical transition metal double perovskite oxide Ca$_2$FeMnO$_6$ Sarkar, Arindam Banerjee, Hrishit Das, Debashish Singh, Prashant Alam, Aftab Materials Science Strongly Correlated Electrons Ca$_2$FeMnO$_6$ (CFMO) double perovskite was studied using first principles density functional theory and tight-binding (TB) Hamiltonian modeling using extended Hubbard model. We have shown by electronic structure analysis that charge- and magnetic-ordering are driven by charge disproportionation at low temperature caused by partial localization of O-$2p$ ligand holes at alternate Fe sites that creates Jahn-Teller distortion, which leads to metal to insulator transition (MIT) in CFMO. Our results suggests MIT was triggered by negative charge-transfer energy of self-hole doping, responsible for symmetry lowering transitions. Notably, the band-gap was found to fundamentally controlled by the strength of the charge-transfer energy, and not by the Mott-Hubbard interactions, which can be modeled by composition, pressure or stoichiometry modulations. The fundamental insights presented in this work will help understand similar physics and mechanisms in other class of perovskites and correlated metals. |
| title | Ligand hole driven metal-insulator transition in a prototypical transition metal double perovskite oxide Ca$_2$FeMnO$_6$ |
| topic | Materials Science Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2302.01545 |