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The Anomalous Skin Effect in Single Crystal Relaxor Ferroelectric PZN-xPT and PMN-xPT

Guangyong Xu·P. M. Gehring·C. Stock·K. Conlon
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Abstract

X-ray and neutron scattering studies of the lead-based family of perovskite relaxors PZN-$x$PT and PMN-$x$PT have documented a highly unusual situation in which the near-surface region of a single crystal can exhibit a structure that is different from that of the bulk when cooled to low temperatures. The near-surface region, or "skin" can also display critical behavior that is absent in the crystal interior, as well as a significantly different lattice spacing. By varying the incident photon energy, and thus the effective penetration depth, x-ray measurements indicate a skin thickness of order 10 $μ$m to 50 $μ$m for PZN-$x$PT samples with $0 \le x \le 8$%. Neutron residual stress measurements on a large PMN single crystal reveal a uniform lattice spacing within the bulk, but an increased strain near the surface. The presence of this skin effect has led to incorrect phase diagrams for both the PZN-$x$PT and PMN-$x$PT systems and erroneous characterizations of the nature of the relaxor state.

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Guangyong Xu, P. M. Gehring, C. Stock, K. Conlon. 2006-08-01. The Anomalous Skin Effect in Single Crystal Relaxor Ferroelectric PZN-xPT and PMN-xPT. https://arxiv.org/abs/cond-mat/0608033

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