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Theoretical studies of charge relaxation effects on the statics and dynamics of oxides

Publication ,  Journal Article
Cohen, RE; Boyer, LL; Mehl, MJ
Published in: Physics and Chemistry of Minerals
May 1, 1987

Inclusion of spherical charge relaxation in response to the long-range electrostatic potential (potential induced breathing, or PIB) gives improved results for the static and dynamic properties of oxides. PIB is a Gordon-Kim type model, in which the crystal charge density is estimated by overlapping ionic charge densities. No experimental data are used, except for the values of universal constants, and in this sense the results are from first principles. In contrast to earlier models which include some form of charge relaxation, we explicitly include the breathing effects on the self-energy and pair potentials in the model Hamiltonian. PIB is a many-body effect that couples the long-and short-range forces in a way that is not present in any other first principles or empirical models. It leads to the observed violations of the Cauchy relations for the elastic constants whereas central force rigid ion models cannot violate the Cauchy relations. PIB also reduces the predicted LO-TO splitting because the breathing effect introduces dynamical effective charges that are lower in magnitude than the ionic charges. Some results are shown and discussed for MgO (periclase), BeO (bromellite), Al2O3 (corundum), TiO2 (rutile) and SiO2 (quartz and stishovite). © 1987 Springer-Verlag.

Duke Scholars

Published In

Physics and Chemistry of Minerals

DOI

EISSN

1432-2021

ISSN

0342-1791

Publication Date

May 1, 1987

Volume

14

Issue

4

Start / End Page

294 / 302

Related Subject Headings

  • Geochemistry & Geophysics
  • 3705 Geology
  • 0912 Materials Engineering
  • 0402 Geochemistry
 

Citation

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Cohen, R. E., Boyer, L. L., & Mehl, M. J. (1987). Theoretical studies of charge relaxation effects on the statics and dynamics of oxides. Physics and Chemistry of Minerals, 14(4), 294–302. https://doi.org/10.1007/BF00309800
Cohen, R. E., L. L. Boyer, and M. J. Mehl. “Theoretical studies of charge relaxation effects on the statics and dynamics of oxides.” Physics and Chemistry of Minerals 14, no. 4 (May 1, 1987): 294–302. https://doi.org/10.1007/BF00309800.
Cohen RE, Boyer LL, Mehl MJ. Theoretical studies of charge relaxation effects on the statics and dynamics of oxides. Physics and Chemistry of Minerals. 1987 May 1;14(4):294–302.
Cohen, R. E., et al. “Theoretical studies of charge relaxation effects on the statics and dynamics of oxides.” Physics and Chemistry of Minerals, vol. 14, no. 4, May 1987, pp. 294–302. Scopus, doi:10.1007/BF00309800.
Cohen RE, Boyer LL, Mehl MJ. Theoretical studies of charge relaxation effects on the statics and dynamics of oxides. Physics and Chemistry of Minerals. 1987 May 1;14(4):294–302.
Journal cover image

Published In

Physics and Chemistry of Minerals

DOI

EISSN

1432-2021

ISSN

0342-1791

Publication Date

May 1, 1987

Volume

14

Issue

4

Start / End Page

294 / 302

Related Subject Headings

  • Geochemistry & Geophysics
  • 3705 Geology
  • 0912 Materials Engineering
  • 0402 Geochemistry