Maxima of effective parameters of novel piezo-composites based on relaxor-ferroelectric single crystals

This paper is devoted to the analysis of effective electromechanical properties and their maxima in 0-3-type composites based on (1 - x)Pb(Mg1/3Nb2/3)O-3 - xPbTiO(3) single crystals. It is shown that the electromechanical interaction between the single-crystal e(33)((n)) / vertical bar e(31)((n))vertical bar and polymer components with the anisotropy of their piezoelectric coefficients e33 31 >= 5 results in relations d(33)* approximate to e(33)* s(33)*(E), g(33)* approximate to h (33)*s(33)*(D) and k(t)* approximate to k(33)* for the electromechanical constants. These relations hold in a wide range of volume fraction and aspect ratio of the spheroidal inclusions in the 0-3 composite. An increase in the maximum values of different effective parameters is expected by.forming a system of oblate air pores in the matrix.