Electrical and Optical Property of Lanthanum Oxide Doped Potassium Sodium Niobate Ceramics

Potassium sodium niobate (K0.5Na0.5NbO3, KNN) based ceramics can be widely used for pulsed power systems due to their fast charge-discharge rate, high transparency, wide range of working temperature, and long cycle life. Improving the electrical and optical property of KNN-based ceramics through modification is a research hotspot in this field. 0.825(K0.5Na0.5)NbO3-0.175Sr(1-3x/2)La(x) (Sc0.5Nb0.5)O-3 (x=0, 0.1, 0.2, 0.3) (0.825KNN-0.175SLSN) ceramics were synthesized by solid state method. The effect of La 2 0 3 doping on the phase structure, microstructure, optical property, dielectric property, ferroelectric property and energy storage property of the ceramic was studied. The results indicated that the structure of 0.825KNN-0.175SLSN ceramics is pseudo-cubic phase with high symmetry. With increment of La2O3 content, the average grain size of 0.825KNN-0.175SLSN ceramics decreased, and the phase transition temperature (T-m) and saturation polarization intensity (P-max) increased and then decreased. 0.825KNN-0.175SLSN ceramics exhibit excellent transparency at x=0.3, the transmittance in the visible wavelength (780 nm) and near-infrared wavelength (1200 nm) ranges reaches 65.2% and 71.5%, respectively. The dielectric breakdown strength of 310 kV/cm and a recoverable energy density of 1.85 J/cm 3 are achieved at x=0.3.