2019 Volume 127 Issue 12 Pages 905-911
The effect of Bi2O3 content on the crystal structure, microstructure, and optical and electric properties of [Li0.05(K0.5Na0.5)0.95]NbO3 + x wt %Bi2O3 ceramics was investigated. These ceramics were fabricated using a conventional pressure-less sintering, and were observed to be opaque at x = 0 and 3 but transparent at x = 5 and 7. The transmittance at an infrared wavelength of 1310 nm was 68 and 62% at x = 5 and 7, respectively. At x = 5, a high Curie temperature of 365°C, a ferroelectric polarization–electric field loop with a reduced remanent polarization, and a quadratic electro-optic effect of 3.1 × 10−17 m2/V2 were observed. The effective linear electro-optic effect (Δn/Eπ) was calculated by the birefringence (Δn) divided by a half-wave electric field (Eπ) of 43.2 kV/cm. This value was equal to 146 pm/V, which was higher than the linear electro-optic effect of previously reported (K,Na)NbO3-based transparent ceramics and a LiNbO3 single crystal. However, it was lower than that of a K(Ta,Nb)O3 single crystal and (Pb,La)(Zr,Ti)O3 transparent ceramics.