Аннотация:Single-phase ceramic samples of new compositions (1‑x)K0.5Na0.5)NbO3‑xSrZrO3 (x = 0‑0.15) modified with the addition of 2 wt % ZnO were obtained via the solid-state synthesis method. Their crystal structures, microstructures, dielectric, and nonlinear optical properties were studied. The modified samples were found to form a phase with a perovskite structure and a pseudocubic unit cell. A decrease in the average crystallite size (coherent scattering regions) from 91 to 54 nm was observed. Ferroelectric phase transitions were confirmed using dielectric spectroscopy. A reduction in the phase transition temperatures and a weakening of nonlinear optical properties were revealed with an increase in the strontium zirconate content in the samples.