Issue |
J. Phys. IV France
Volume 128, September 2005
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Page(s) | 47 - 53 | |
DOI | https://doi.org/10.1051/jp4:2005128008 |
J. Phys. IV France 128 (2005) 47-53
DOI: 10.1051/jp4:2005128008
The role of Pb in piezoelectrics and possible substitutions for it
D.J. Singh1, M. Ghita2, S.V. Halilov3 and M. Fornari21 Condensed Matter Sciences Div., Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
2 Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859, USA
3 R.J. Mears, LLC, 1100 Winter St., Waltham, MA 02451, USA
Abstract
The interplay between the various patterns of structural
instability that are related to the electromechanical coupling in
ferroelectric perovskites is discussed using results of density functional
based first principles calculations. We focus on two main issues: (1) the
competition between tetragonal and rhombohedral ferroelectric states in
A-site driven (tolerance factor, t<1) perovskites, and (2) the competition of
ferroelectricity and antiferroelectric octahedral rotation. The role of Pb
is reviewed in terms of cross gap hybridization of Pb 6p states with O 2p
orbitals, and an alternate mechanism for reducing the tendency towards tilt
instabilities in low tolerance factor perovskites based on frustration is
discussed.
© EDP Sciences 2005