Lattice dynamics of BaTiO3, PbTiO3, and PbZrO3: a comparative first-principles study

Ghosez, Ph. ; Cockayne, E. ; Waghmare, U. V. ; Rabe, K. M. (1999) Lattice dynamics of BaTiO3, PbTiO3, and PbZrO3: a comparative first-principles study Physical Review B: Condensed Matter and Materials Physics, 60 (2). pp. 836-843. ISSN 1098-0121

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Official URL: http://prb.aps.org/abstract/PRB/v60/i2/p836_1

Related URL: http://dx.doi.org/10.1103/PhysRevB.60.836

Abstract

The full phonon dispersion relations of lead titanate and lead zirconate in the cubic perovskite structure are computed using first-principles variational density-functional perturbation theory, with ab initio pseudopotentials and a plane-wave basis set. Comparison with the results previously obtained for barium titanate shows that the change of a single constituent (Ba to Pb, Ti to Zr) has profound effects on the character and dispersion of unstable modes, with significant implications for the nature of the phase transitions and the dielectric and piezoelectric responses of the compounds. Examination of the interatomic force constants in real space, obtained by a transformation which correctly treats the long-range dipolar contribution, shows that most are strikingly similar, while it is the differences in a few key interactions which produce the observed changes in the phonon dispersions. These trends suggest the possibility of the transferability of force constants to predict the lattice dynamics of perovskite solid solutions.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:59425
Deposited On:06 Sep 2011 05:18
Last Modified:18 May 2016 10:00

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