Point defects of La2CuO4-based ceramics, part I: Oxygen interstitials

Yue Wu, Donald E. Ellis, Li Shen, Thomas O Mason

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Theoretical and experimental studies are reported on oxygen excess defect structure of lanthanum cuprate, La2CuO4+δ. The local density functional formalism is applied to theoretical analysis. The self-consistent discrete variational method has been used to find energy levels, densities of states, charge transfer, wavefunctions, and potentials for a fragment consisting of N (30-44) atoms embedded in the infinite crystal. Calculations have been performed on three interstitial oxygen models, with and without local relaxations. These models include sites proposed on the basis of neutron diffraction and interstitial dimers [O2]q. The dimer charge q is found to be consistent with that of normal oxygens, and not -1 as proposed in "superoxide" models. Electrostatic energies are used to estimate the relative stabilities of the proposed interstitial structures. The experimental Seebeck coefficient also shows that the charge of interstitial oxygen is -2. Effective atomic configurations for the ideal lattice are compared with those in the vicinity of the defects, and defect-related spectroscopic consequences are examined.

Original languageEnglish
Pages (from-to)1599-1604
Number of pages6
JournalJournal of the American Ceramic Society
Volume79
Issue number6
Publication statusPublished - Jun 1996

Fingerprint

Point defects
Oxygen
Dimers
Lanthanum
Defects
Seebeck coefficient
Defect structures
Neutron diffraction
Wave functions
Superoxides
Electron energy levels
Charge transfer
Electrostatics
Atoms
Crystals
La2CuO4

ASJC Scopus subject areas

  • Ceramics and Composites

Cite this

Point defects of La2CuO4-based ceramics, part I : Oxygen interstitials. / Wu, Yue; Ellis, Donald E.; Shen, Li; Mason, Thomas O.

In: Journal of the American Ceramic Society, Vol. 79, No. 6, 06.1996, p. 1599-1604.

Research output: Contribution to journalArticle

Wu, Yue ; Ellis, Donald E. ; Shen, Li ; Mason, Thomas O. / Point defects of La2CuO4-based ceramics, part I : Oxygen interstitials. In: Journal of the American Ceramic Society. 1996 ; Vol. 79, No. 6. pp. 1599-1604.
@article{9c3500495fa7408d9774e86001aea265,
title = "Point defects of La2CuO4-based ceramics, part I: Oxygen interstitials",
abstract = "Theoretical and experimental studies are reported on oxygen excess defect structure of lanthanum cuprate, La2CuO4+δ. The local density functional formalism is applied to theoretical analysis. The self-consistent discrete variational method has been used to find energy levels, densities of states, charge transfer, wavefunctions, and potentials for a fragment consisting of N (30-44) atoms embedded in the infinite crystal. Calculations have been performed on three interstitial oxygen models, with and without local relaxations. These models include sites proposed on the basis of neutron diffraction and interstitial dimers [O2]q. The dimer charge q is found to be consistent with that of normal oxygens, and not -1 as proposed in {"}superoxide{"} models. Electrostatic energies are used to estimate the relative stabilities of the proposed interstitial structures. The experimental Seebeck coefficient also shows that the charge of interstitial oxygen is -2. Effective atomic configurations for the ideal lattice are compared with those in the vicinity of the defects, and defect-related spectroscopic consequences are examined.",
author = "Yue Wu and Ellis, {Donald E.} and Li Shen and Mason, {Thomas O}",
year = "1996",
month = "6",
language = "English",
volume = "79",
pages = "1599--1604",
journal = "Journal of the American Ceramic Society",
issn = "0002-7820",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Point defects of La2CuO4-based ceramics, part I

T2 - Oxygen interstitials

AU - Wu, Yue

AU - Ellis, Donald E.

AU - Shen, Li

AU - Mason, Thomas O

PY - 1996/6

Y1 - 1996/6

N2 - Theoretical and experimental studies are reported on oxygen excess defect structure of lanthanum cuprate, La2CuO4+δ. The local density functional formalism is applied to theoretical analysis. The self-consistent discrete variational method has been used to find energy levels, densities of states, charge transfer, wavefunctions, and potentials for a fragment consisting of N (30-44) atoms embedded in the infinite crystal. Calculations have been performed on three interstitial oxygen models, with and without local relaxations. These models include sites proposed on the basis of neutron diffraction and interstitial dimers [O2]q. The dimer charge q is found to be consistent with that of normal oxygens, and not -1 as proposed in "superoxide" models. Electrostatic energies are used to estimate the relative stabilities of the proposed interstitial structures. The experimental Seebeck coefficient also shows that the charge of interstitial oxygen is -2. Effective atomic configurations for the ideal lattice are compared with those in the vicinity of the defects, and defect-related spectroscopic consequences are examined.

AB - Theoretical and experimental studies are reported on oxygen excess defect structure of lanthanum cuprate, La2CuO4+δ. The local density functional formalism is applied to theoretical analysis. The self-consistent discrete variational method has been used to find energy levels, densities of states, charge transfer, wavefunctions, and potentials for a fragment consisting of N (30-44) atoms embedded in the infinite crystal. Calculations have been performed on three interstitial oxygen models, with and without local relaxations. These models include sites proposed on the basis of neutron diffraction and interstitial dimers [O2]q. The dimer charge q is found to be consistent with that of normal oxygens, and not -1 as proposed in "superoxide" models. Electrostatic energies are used to estimate the relative stabilities of the proposed interstitial structures. The experimental Seebeck coefficient also shows that the charge of interstitial oxygen is -2. Effective atomic configurations for the ideal lattice are compared with those in the vicinity of the defects, and defect-related spectroscopic consequences are examined.

UR - http://www.scopus.com/inward/record.url?scp=0030169768&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030169768&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0030169768

VL - 79

SP - 1599

EP - 1604

JO - Journal of the American Ceramic Society

JF - Journal of the American Ceramic Society

SN - 0002-7820

IS - 6

ER -