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First principles studies of the Born effective charges and electronic dielectric tensors for the relaxor PMN (PbMg1/3Nb2/3O3)

Narayani Choudhury·R. E. Cohen·Eric J. Walter
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Abstract

We report first principles density functional calculations of the Born effective charges and electronic dielectric tensors for the relaxor PMN (PbMg1/3Nb2/3O3). Visualization of the Born charge tensors as charge ellipsoids have provided microscopic insights on the factors governing piezoelectric enhancements with polarization rotation. Several 15 and 30-atom ferroelectric and antiferroelectric supercells of PMN involving 1:2 and 1:1 chemical ordering have been studied. A cascading set of ferroelectric phonon instabilities lead to several low symmetry monoclinic structures. We find a ground state with a 15-atom unit cell with 1:2 chemical ordering along [111] with a monoclinic C2 structure.

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Narayani Choudhury, R. E. Cohen, Eric J. Walter. 2006-03-20. First principles studies of the Born effective charges and electronic dielectric tensors for the relaxor PMN (PbMg1/3Nb2/3O3). https://doi.org/10.1016/j.commatsci.2005.12.038

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