Hot-pressing and Characterization of Potassium Sodium Niobate, (K₀.₅Na₀.₅)NbO₃ Incorporated with Tungsten (W-KNN)

Author(s):

Latha Nataraj and Tucker Moore

Abstract:

Multifunctional potassium sodium niobate, (K_0.5Na_0.5)NbO₃ (KNN) has emerged as one of the most promising, lead-free, nontoxic, environment-friendly, and biocompatible candidates to replace high-performing, lead-based piezoelectric materials. It is well known that obtaining phase-pure materials with a high density and a uniform, fine-grained microstructure is a major challenge. In addition, KNN is known for poor densification and an extremely narrow range of sintering temperature (also very close to the solidus temperature) that some studies have attributed to the coarsening of the microstructure without densification, which contributes to a reduction of the driving force for sintering. Here, we report our success at the US Army Combat Capabilities Development Command Army Research Laboratory in developing a tailored hot-pressing technique to obtain well-sintered KNN compacts with high density and characterizing their properties.