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

A quest for non-toxic alternatives to conventional lead-based ferroelectric and piezoelectric materials has 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 pose challenges to ensuring chemical homogeneity and achieving desired structures. Further, it has been demonstrated that doping positively influences properties such as morphology, texture, crystalline structure, and polarization of KNN. Here, we report solvent-free mechanochemical synthesis of single-phase lead-free piezoelectric perovskite oxide (W-KNN) of KNN incorporated with Tungsten (W), 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 material synthesized. Local piezoelectricity is confirmed on the synthesized material for various application-specific device configurations. The presented method could also pave the way for a rapid, facile, and faster synthesis mechanisms at lower processing temperatures for other promising functional oxides.