Abstract:
The system of modified reception parameters of fibrous piezoactive composites “system of unidirectional ferroelectric crystalline rods–polymer matrix” with 1–3 connectivity is studied in a wide range of volume fractions of the crystalline component. The modified reception parameters are important for estimating the efficiency of harvesting, accumulation, and conversion of energy in a piezoelectric cell at a constant mechanical stress or at a constant strain. Polydomain crystals $(1-x)$Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$–$x$PbTiO$_{3}$ (at 0.28 $\le x\le$ 0.33) and Li$_{v}$(K$_{1-y}$Na$_{y}$)$_{1-v}$(Nb$_{1-z}$ Ta$_{z}$)O$_{3}$:Mn crystals (at $v$ = 0.06, $y$ = 0.1 – 0.3, $z$ = 0.07 – 0.17) poled along the [001] crystallographic direction are used as a piezoelectric component. The parameters calculated for 1–3 composites using the matrix method and the effective field method are compared. The role of electromechanical properties of the crystalline component in the formation of the modified reception parameters of composite reception is analyzed. The results of numerical simulation of the effective properties and modified reception parameters associated with them demonstrate the advantages of lead-free 1–3 composite over analogs based on $(1-x)$Pb(Mg$_{1/3}$ Nb$_{2/3}$)O$_{3}$–$x$PbTiO$_{3}$.
Keywords:piezo-active composite, effective electromechanical properties, figure of merit, anisotropy factor, lead-containing and lead-free components.