Improved transmittance and ferroelectric properties realized in KNN ceramics via SAN modification

Transparent, Sr(Al0.5Nb0.5)O-3-modified K0.5Na0.5NbO3 (KNN) ceramics were successfully fabricated by a solid-state pressureless sintering method in this work. The obtained microstructure, transmittance, and electrical properties were characterized in detail. Our results indicated that the modification by Sr(Al0.5Nb0.5)O-3 significantly limited the grain growth behavior of KNN, resulting in dense ceramics with submicron grain size (<0.5m) and small pore size. Consequently, the ceramic with the 0.96K(0.5)Na(0.5)NbO(3)-0.04Sr(Al0.5Nb0.5)O-3 composition showed superior transmittance and electrical properties: T=55% in the visible region (0.78m), d(33)=105pC/N, epsilon(r)=1021, and P-r=15.1C/cm(2), which were significantly higher than those of pure KNN. Our findings implied that the addition of Sr(Al0.5Nb0.5)O-3 could be a good strategy to obtain superior transmittance and electrical properties in KNN and may shed light on other ferroelectric systems.