Role of Domain Orientations in Forming the Hydrostatic Performance of Novel 2-2 Single Crystal/Polymer Composites

• Published in: Ferroelectrics Vol. 444; no. 1; pp. 84 - 99
• Main Authors: Topolov, V. Yu, Bowen, C. R., Krivoruchko, A. V.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis Group 01.01.2013; Taylor & Francis Ltd
• Subjects: Anisotropy; Composite; Crystallographic orientation; Crystallography; Elastic anisotropy; Ferroelectric; Ferroelectrics; Fluid dynamics; Hydrostatic piezoelectric response; Hydrostatics; Orientation; Perovskite; Piezoelectricity; Polymer matrix composites; Polyvinylidene fluorides; Single crystals
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150193.2013.786556

This paper reports results of a detailed study of the effects of the crystallographic orientation on the performance of the 2-2 parallel-connected composites based on relaxor-ferroelectric single crystals of 0.72Pb(Mg 1/3 Nb 2/3 )O 3 -0.28PbTiO 3 . These single crystals are poled along one of the following directions in the perovskite unit cell: [111] (single-domain state), [001] and [011] (polydomain states). The effect of the orientation of the main crystallographic axes in the single-crystal component on the hydrostatic piezoelectric coefficients d* h , e* h and g* h , squared hydrostatic figure of merit d* h  g* h and hydrostatic electromechanical coupling factor k* h of the composites is studied for three cases of the poling direction of 0.72Pb(Mg 1/3 Nb 2/3 )O 3 -0.28PbTiO 3 . Maximum values of the hydrostatic parameters in the 2-2 0.72Pb(Mg 1/3 Nb 2/3 )O 3 -0.28PbTiO 3 / polyvinylidene fluoride composites are d* h = 372 pC / N, g* h = 284 mV.m/N, d* h g* h = 33.8.10 −12 Pa −1 , and k* h = 0.361 (in the presence of the [011]-poled single crystal), and e* h = 45.1 C/m 2 (in the presence of the [111]-poled single crystal). The inequality k* 33 /|k* 3j | ≥ 5 (j = 1 and 2) is valid for the composite based on the [111]-poled single crystal under specific conditions. The composites exhibit remarkable properties, and the elastic and piezoelectric anisotropy of the single-crystal component (either [111]- or [011]-poled) plays an important role in achieving the large hydrostatic parameters.