Localization Mechanism of Interstitial Electronic States in Electride Mayenite

Dmitry Y Novoselov; Mary A Mazannikova; Dmitry M Korotin; Alexey O Shorikov; Michael A Korotin; Vladimir I Anisimov; Artem R Oganov

doi:10.1021/acs.jpclett.2c02002

Localization Mechanism of Interstitial Electronic States in Electride Mayenite

J Phys Chem Lett. 2022 Aug 11;13(31):7155-7160. doi: 10.1021/acs.jpclett.2c02002. Epub 2022 Jul 29.

Authors

Dmitry Y Novoselov^{1

2

3}, Mary A Mazannikova^{1

2}, Dmitry M Korotin^{1

3}, Alexey O Shorikov^{1

2

3}, Michael A Korotin¹, Vladimir I Anisimov^{1

2

3}, Artem R Oganov³

Affiliations

¹ M. N. Mikheev Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, 18 S. Kovalevskaya Street, Yekaterinburg620108, Russia.
² Department of theoretical physics and applied mathematics, Ural Federal University, 19 Mira Street, Yekaterinburg620002Russia.
³ Skolkovo Institute of Science and Technology, 3 Nobel Street, Moscow143026, Russia.

PMID: 35904271
DOI: 10.1021/acs.jpclett.2c02002

Abstract

Electrides contain interstitial electrons with the states that are spatially separated from the crystal framework states and form a detached electronic subsystem. In mayenite [Ca₁₂Al₁₄O₃₂]²⁺(e^-)₂ interstitial electrons form a unique charge network where localization and delocalization coexist, pointing to the importance of investigating the many-body nature of electride states. Using density functional theory and dynamical mean-field theory, we show a tendency toward electron localization and antiferromagnetic pairing, which leads to the formation of an experimentally observed peak under the Fermi level. The effect is associated with strong hybridization between interstitial electronic states, which removes the degeneracy and leads to the formation of a singlet state on a bonding molecular orbital as well as with the Coulomb interaction between interstitial electrons. Our work provides a fundamental understanding of the localization mechanism of interstitial electrons in mayenite and proposes a new approach for a proper description of the electronic subsystem of mayenite and other electrides.