2001/10/25 by T. Y. Koo, T. -Y. Koo, P. M. Gehring +6
Engineering · Materials Science · Physics and Astronomy · #Acoustic Wave Resonator Technologies #Ferroelectric and Piezoelectric Materials #Microwave Dielectric Ceramics Synthesis #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.65.144113
6 pages, 4 figures
arxiv created 2001/10/25 · openalex publication_date 2002/04/04 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The intrinsic linewidth \ensuremathΓTA of the transverse acoustic phonon observed in the relaxor ferroelectric compound Pb(Mg1/3Nb2/3)0.8Ti0.2O3 (PMN-20%PT) begins to broaden with decreasing temperature around 650 K, nearly 300 K above the ferroelectric transition temperature Tc (\ensuremath∼360 K). We speculate that this anomalous behavior is directly related to the condensation of polarized, nanometer-sized, regions (PNR) at the Burns temperature Td. We also observe the ``waterfall'' anomaly previously seen in pure PMN, in which the transverse optic branch appears to drop precipitously into the TA branch at a finite momentum transfer qwf\ensuremath∼0.15 \mathrm\AA^\ensuremath-1. The waterfall feature is seen even at temperatures above Td. This latter result suggests that the PNR exist as dynamic entities above Td.