Griffiths-like behavior of a disordered antiferroelectric
Abstract
Large non-linear effects are found in a well-defined temperature range above the Neel temperature in the disordered antiferroelectric Pb_0.97La_0.02(Zr_0.60Sn_0.30Ti_0.10)O_3. The linear dielectric susceptibility vs. T shows a sharply defined plateau in this regime. The loss tangent is very low in this regime, so the plateau cannot be attributed to kinetic effects. The sign of the non-linearity is opposite to that expected for ferroelectric clusters. Although the dependence of the dielectric susceptibility on dc fields is analytic, there is an extended regime of third-harmonic generation which appears non-analytic as a function of ac field amplitude. This pseudo-nonanalyticity extends down to fields of about 200V/cm. The phase of nonlinear effects from mixed frequency inputs appears inconsistent with simple coercive-field explanations. We attribute these effects to Griffiths-like clusters of antiferroelectric order, consistent with previous scattering studies^1. 1. W.-H Chan et al., JAP 94, 4563 (2003) Work supported by NSF DMR 0240644 and RGC CERG 9040688.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARD20006C