TY - JOUR

T1 - Electronic Transport via Interstitial States in Mayenite Electride

AU - Mazannikova, Mary a.

AU - Korotin, Dmitry m.

AU - Shorikov, Alexey o.

AU - Anisimov, Vladimir i.

AU - Novoselov, Dmitry y.

N1 - The DFT part of the study was supported by the Ministry of Science and Higher Education of the Russian Federation (no. AAAA-A18-118020190098-5, topic Electron) . The MLWF and electronic transport calculations were carried out within the state assignment of the Russian Science Foundation (project 19-12-00012) .

PY - 2023/5/11

Y1 - 2023/5/11

N2 - Earlier theoretical calculations of the Seebeck coefficient of mayenite electride have shown that electrons are the major type of charge carriers, while experimental measurements show that the carriers are holes. We investigated the interplay between the experimentally observed deformation of Ca-Al-O cages in mayenite electride and its transport properties to reveal the reasons for this discrepancy. We found that the deformation of individual cages lifts the degeneracy of the electride subsystem and induces the localization of electrons in these interstices. This leads to significant changes in the band structure near the Fermi level, accompanied by splitting of the electride states into two subsystems separated by an indirect energy gap. As a result, the sign of the Seebeck coefficient changes and becomes positive, indicating that holes are the main type of charge carriers in accordance with the experimental observations. This outcome confirms that the mayenite electride subsystem cannot be considered as a homogeneous gas of free electrons but should be considered as partially localized electrons that can move through the crystal together with local deformations.

AB - Earlier theoretical calculations of the Seebeck coefficient of mayenite electride have shown that electrons are the major type of charge carriers, while experimental measurements show that the carriers are holes. We investigated the interplay between the experimentally observed deformation of Ca-Al-O cages in mayenite electride and its transport properties to reveal the reasons for this discrepancy. We found that the deformation of individual cages lifts the degeneracy of the electride subsystem and induces the localization of electrons in these interstices. This leads to significant changes in the band structure near the Fermi level, accompanied by splitting of the electride states into two subsystems separated by an indirect energy gap. As a result, the sign of the Seebeck coefficient changes and becomes positive, indicating that holes are the main type of charge carriers in accordance with the experimental observations. This outcome confirms that the mayenite electride subsystem cannot be considered as a homogeneous gas of free electrons but should be considered as partially localized electrons that can move through the crystal together with local deformations.

UR - https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=tsmetrics&SrcApp=tsm_test&DestApp=WOS_CPL&DestLinkType=FullRecord&KeyUT=000982441500001

UR - http://www.scopus.com/inward/record.url?partnerID=8YFLogxK&scp=85156244268

U2 - 10.1021/acs.jpcc.2c08517

DO - 10.1021/acs.jpcc.2c08517

M3 - Article

VL - 127

SP - 8714

EP - 8719

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 18

ER -