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Title: Self-consistent cluster-embedding calculation method and the calculated electronic structure of NiO

Abstract

The self-consistent cluster-embedding method is discussed theoretically. A definition of the total energy for an embedded cluster has been introduced. The method has two advantages. (i) It can describe both localized and band properties, including their excitations. (ii) It can give a good description of the magnetic properties for both spin-ordered and spin-disordered states. The electronic structure of NiO is studied using a high-quality basis set to calculate the electronic structure of a small embedded cluster and an antiferromagnetic insulating ground state is obtained. The picture has both localized and band properties. A small energy gap separates the unoccupied and occupied nickel 3[ital d] orbitals which are well localized. Each 3[ital d] orbital is attached to a particular nickel ion. Below the 3[ital d] levels are two diffuse oxygen 2[ital p] bands, and above the 3[ital d] levels are oxygen 3[ital s], nickel 4[ital s], and oxygen 3[ital p] bands. Experimental data concerning photoemission and optical absorption can be interpreted naturally. The spin magnetic moment of the nickel ion is calculated correctly. The simulation of the spin-disordered state shows that NiO remains as an insulator in the paramagnetic state. The Neel temperature of NiO is calculated directly to give amore » reasonable result. The Hubbard [ital U] parameter for nickel 3[ital d] electrons is estimated. The calculation shows that the excited nickel 3[ital d] electrons are also well localized and the overlaps are less than 4.5%. We propose the following: The overlap of the excited 3[ital d] electrons is too small to form a metallic band, but the overlap is sufficient for the hole'' to migrate through the crystal. In this sense, NiO is a charge-transfer insulator with a gap of about 4 eV (mostly from oxygen to nickel).« less

Authors:
 [1]
  1. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
Publication Date:
OSTI Identifier:
5573434
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter; (United States)
Additional Journal Information:
Journal Volume: 48:20; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ELECTRONIC STRUCTURE; CALCULATION METHODS; NICKEL OXIDES; ACTIVATION ENERGY; CHARGE EXCHANGE; CLUSTER EXPANSION; ENERGY GAP; SELF-CONSISTENT FIELD; CHALCOGENIDES; ENERGY; NICKEL COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; SERIES EXPANSION; TRANSITION ELEMENT COMPOUNDS; 665000* - Physics of Condensed Matter- (1992-); 360204 - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats

Zheng, H. Self-consistent cluster-embedding calculation method and the calculated electronic structure of NiO. United States: N. p., 1993. Web. doi:10.1103/PhysRevB.48.14868.
Zheng, H. Self-consistent cluster-embedding calculation method and the calculated electronic structure of NiO. United States. doi:10.1103/PhysRevB.48.14868.
Zheng, H. Mon . "Self-consistent cluster-embedding calculation method and the calculated electronic structure of NiO". United States. doi:10.1103/PhysRevB.48.14868.
@article{osti_5573434,
title = {Self-consistent cluster-embedding calculation method and the calculated electronic structure of NiO},
author = {Zheng, H},
abstractNote = {The self-consistent cluster-embedding method is discussed theoretically. A definition of the total energy for an embedded cluster has been introduced. The method has two advantages. (i) It can describe both localized and band properties, including their excitations. (ii) It can give a good description of the magnetic properties for both spin-ordered and spin-disordered states. The electronic structure of NiO is studied using a high-quality basis set to calculate the electronic structure of a small embedded cluster and an antiferromagnetic insulating ground state is obtained. The picture has both localized and band properties. A small energy gap separates the unoccupied and occupied nickel 3[ital d] orbitals which are well localized. Each 3[ital d] orbital is attached to a particular nickel ion. Below the 3[ital d] levels are two diffuse oxygen 2[ital p] bands, and above the 3[ital d] levels are oxygen 3[ital s], nickel 4[ital s], and oxygen 3[ital p] bands. Experimental data concerning photoemission and optical absorption can be interpreted naturally. The spin magnetic moment of the nickel ion is calculated correctly. The simulation of the spin-disordered state shows that NiO remains as an insulator in the paramagnetic state. The Neel temperature of NiO is calculated directly to give a reasonable result. The Hubbard [ital U] parameter for nickel 3[ital d] electrons is estimated. The calculation shows that the excited nickel 3[ital d] electrons are also well localized and the overlaps are less than 4.5%. We propose the following: The overlap of the excited 3[ital d] electrons is too small to form a metallic band, but the overlap is sufficient for the hole'' to migrate through the crystal. In this sense, NiO is a charge-transfer insulator with a gap of about 4 eV (mostly from oxygen to nickel).},
doi = {10.1103/PhysRevB.48.14868},
journal = {Physical Review, B: Condensed Matter; (United States)},
issn = {0163-1829},
number = ,
volume = 48:20,
place = {United States},
year = {1993},
month = {11}
}