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

Abstract Transparent, Sr(Al 0.5 Nb 0.5 )O 3 ‐modified K 0.5 Na 0.5 NbO 3 (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(Al 0.5 Nb 0.5 )O 3 significantly limited the grain growth behavior of KNN, resulting in dense ceramics with submicron grain size (<0.5 μm) and small pore size. Consequently, the ceramic with the 0.96K 0.5 Na 0.5 NbO 3 ‐0.04Sr(Al 0.5 Nb 0.5 )O 3 composition showed superior transmittance and electrical properties: T = 55% in the visible region (0.78 μm), d 33 = 105 pC/N, ε r = 1021, and P r = 15.1 μC/cm 2 , which were significantly higher than those of pure KNN. Our findings implied that the addition of Sr(Al 0.5 Nb 0.5 )O 3 could be a good strategy to obtain superior transmittance and electrical properties in KNN and may shed light on other ferroelectric systems.