Effects of Ba(Mg 1/3 Ta 2/3 )O 3 doping on phase structure, optical and electrical properties of (K 0.5 Na 0.5 )NbO 3 transparent ferroelectric ceramics

This paper takes KNN ceramics as the research object, and introduces the second component of ABO 3 type perovskite structure into it. A series of (1- x )K 0.5 Na 0.5 NbO 3 - x Ba(Mg 1/3 Ta 2/3 )O 3 ( x = 0.02, 0.03, 0.04, 0.05, 0.06, 0.07) (KNN- x BMT) nanostructured ferroelectric transparent ceramics were successfully synthesized by solid-phase reaction. The effects of BMT on the optical permeability, phase transition, microstructure and electrical properties of KNN ceramics were systematically studied. It is found that when the BMT content x = 0.05, the transmittance of the ceramic at 1100 nm wavelength reached 68%, and ceramic has the smallest grain size and a concentrated grain size distribution range. Compared with pure KNN ceramics, these nanostructured ceramics have better optical transmittance. The formation of pseudo-cubic phase in ceramics at x ≥ 0.04 promotes the enhanced relaxation of ceramics, and the hysteresis loop becomes elongated. The maximum polarization ( P m ) of the ceramics is reduced, and the energy storage efficiency ( η ) reaches a maximum of 65%. When the BMT content x is over 0.04, the two peaks in the dielectric temperature spectrum gradually merged with the increase of BMT content, and the phase transition temperature ( T m ) shifted to low temperature. This shows that the BMT addition increases the relaxivity of the ceramics.