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Possible Coexistence of Rotational and Ferroelectric Lattice Distortions in Rhombohedral PZT

M. Fornari·D. J. Singh
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Abstract

The competitions between ferroelectric and rotational instabilities in rhombohedral PZT near x = 0.5 are investigated using first principles density functional supercell calculations. As expected, we find a strong ferroelectric instability. However, we also find a substantial R-point rotational instability, close to but not as deep as the ferroelectric one. This is similar to the situation in pure PbZrO_3. These two instabilities are both strongly pressure dependent, but in opposite directions so that lattice compression of less than 1% is sufficient to change their ordering. Because of this, local stress fields due to B-site cation disorder may lead to coexistence of both types of instability are likely present in the alloy near the morphotropic phase boundary.

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M. Fornari, D. J. Singh. 2000-12-07. Possible Coexistence of Rotational and Ferroelectric Lattice Distortions in Rhombohedral PZT. https://doi.org/10.1103/physrevb.63.092101

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