Processing and Properties of Textured Potassium Sodium Niobate [K,Na]NbO3 Ceramic Ribbons by Alginate Gelation Method

Abstract

Random and < 001 > textured potassium sodium niobate - [K,Na]NbO3 (KNN) ceramics with 1 mole% CuO sintering aid were fabricated in ribbon form through a combination of novel alginate gelation process and templated grain growth methods using platelike sodium niobate - NaNbO3 (NN) template particles. The platelike NN template particles were prepared by a two-step molten salt synthesis method. Ribbons were drawn from alginate-based slurries without or with 10 wt% NN template particles using 50mm long slit nozzle with a rectangular orifice of 10mmx1mm. Development of crystallographic texture as a result of varying sintering time and temperature was evaluated through the calculation of the degree of orientation as measured by the Lotgering factor (integral((001))) and an integral((001)) of 0.81 was achieved. The electrical properties of textured ribbons were evaluated with polarization and strain versus electric field measurements.