Heliyon (Feb 2020)
Multi-element ferroactive materials based on KNN-PZT compositions with fundamentally different physical properties
Abstract
Quasibinary section solid solutions of a four-component system of the (1-x)(Na0.5K0.5)NbO3-xPb(Ti0.5Zr0.5)O3 composition, based on compositions with fundamentally different physical responses (Na, K)NbO3(KNN), Pb(Ti, Zr)O3 (PZT), have been produced by two-step solid-phase synthesis followed by sintering using conventional ceramic technology. The features of their structural formation have been revealed, a phase diagram of equilibria has been constructed, correlation relationships composition ‒ structure ‒ microstructure ‒ macroproperties have been established. Based on the measured X-ray fluorescence intensities, the concentrations of chemical elements, included in the surface composition of the samples of piezoceramic materials, have been determined. Statistical characteristics and variations in the chemical composition of the structure-forming chemical elements of the ferroactive composite materials were researched. Micro-XRF combined with methods of mathematical statistics provides to characterize a degree of chemical homogeneity and statistically compare the average concentrations of the chemical elements. Changes in atomic concentrations were revealed as result of varying technological conditions of synthesis. We have carried out the X-ray quantitative analysis for the thickness of surface layer corresponding to the chemical elements at the depth yield of X-ray fluorescence. Three groups of solid solutions ‒ the foundations of intelligent materials have been identified: with high Kp, ε33T/ε0 low V1E (near PZT) – promising for low-frequency applications; with low ε33T/ε0, high V1E (near KNN) ‒ for high-frequency use; with intermediate values of the piezoelectric parameters (near SS1→SS2 ‒ transition), intended for operation in combined equipment complexes.
