Polarization orientation effect and combination of electromechanical properties in advanced 0.67Pb(Mg(1/3)Nb(2/3))O(3)-0.33PbTiO(3) single crystal/polymer composites with 2-2 connectivity

A comparative study on the effective piezoelectric properties and hydrostatic piezoelectric response is first carried out for advanced 2-2 composites based on single crystals of relaxor-ferroelectric solid solutions. Different orientations of domains and different poling directions of components are taken into consideration in the analysis of the effective longitudinal piezoelectric coefficients d*(33) e*(33), g*(33) and hydrostatic piezoelectric coefficients d*(h), h*(e) and g*(h). The important role of the polarization orientation effect and the effect of combination of the electromechanical properties in attaining the large effective parameters is shown for the parallel-connected 2-2 single-domain 0.67Pb(Mg(1/3)Nb(2/3))O(3)-0.33PbTiO(3)/polyvinylidene fluoride composite. In particular, near extremum points of the effective parameters, this composite is characterized by the piezoelectric coefficients g*(33) - 500 mV m N(-1), ''d*(h)'' - 400 pC N(-1), ''e*(h)''-40 C m(-2), and g*(h) - 400 mV m N(-1). Three piezo-sums are first found to describe major contributions of the piezoelectric coefficients d*(ij), e*(ij) and g*(ij) to d*(h), e*(h) and g*(h), respectively, in the vicinity of absolute maxima (minima) of the aforementioned hydrostatic parameters. Advantages concerned with the presence of the single crystal (either single-domain or polydomain) in the studied 2-2 composites are discussed in connection with their piezoelectric activity, sensitivity and hydrostatic response.