Solvent-Free Mechanochemical Synthesis of Lead-Free Piezoelectric Perovskite Potassium Sodium Niobate Incorporated with Tungsten

Author(s):

Latha Nataraj, Anthony Roberts, Scott Walck, Tucker Moore, and Kristopher Darling

Abstract:

A quest for nontoxic alternatives to conventional lead-based ferroelectric and piezoelectric materials led to avid research in complex perovskite oxides and systems characterized by morphotropic phase boundary due to the abrupt increase in the dielectric and piezoelectric constants occurring in this region. Niobate perovskites like the (K, Na) NbO₃ (KNN) family have emerged as some of the most important lead-free ferroelectric and piezoelectric materials. Engineering of facile, economical, and environmentally safe synthesis methods for such materials poses challenges to ensuring chemical homogeneity and achieving desired structures. Here, we report solvent-free mechanochemical synthesis of single-phase lead-free piezoelectric perovskite oxide (W-KNN) of KNN incorporated with tungsten, using a simple high-energy ball-milling process with shorter processing times and lower calcination temperatures than those reported in literature. The characterization of the derived powder confirms the structure, morphology, crystallinity, and chemical composition of the synthesized material. The presented method could also pave the way for a rapid, facile, and faster synthesis mechanism at lower processing temperatures for other promising functional oxides.