Introduction of Sr(In0.5Ta0.5)O3 to Modulate Phase Structure and Optoelectronic Properties of (K0.5Na0.5)NbO3 Ceramics

Pressureless solid-phase sintering was used to prepare (1 − x)K0.5Na0.5NbO3-xSr(In0.5Ta0.5)O3 (KNN-xSInT, x = 0.02, 0.03 0.04, 0.05, 0.06, 0.07) ceramics, and effects of SInT doping on the phase structure, microstructure, optical, and electrical properties in ceramics were investigated. With an increase in SInT content, the structure of KNN-xSInT ceramics gradually changes from orthogonal to pseudo-cubic . When x = 0.04, the near-infrared band (1100 nm) transmittance of the ceramics reaches 46.92%, and the optical band gap (Eg) is 3.11 eV. The maximum dielectric constant (εr) is 4990 at x = 0.02, and a maximum d33 value of 95 pC/N is obtained at x = 0.03. The KNN-xSInT ceramic sample has characteristics of relaxation ferroelectrics, which is an environmentally friendly, lead-free transparent ferroelectric ceramic.