Morphogenesis mechanisms in the hydrothermal growth of lead-free BCZT nanostructured multipods

Abstract

Due to growing environmental concerns about the toxicity of lead-based piezoelectrics, the replacement of Pb-based materials with homologs with comparable piezoelectric properties but without lead is an emergent task. Since 2009, Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) materials have aroused considerable attention as a replacement due to their excellent dielectric, ferroelectric and piezoelectric properties. Nanostructuring of BCZT can enhance these functionalities even more. Here, templated-growth of BCZT nanostructured multipods with hydrogen zirconate titanate nanowires (HZTO-NWs) was investigated under hydrothermal conditions. The effects of the precursor's concentrations and the hydrothermal reaction time on the morphological formation of BCZT nanostructures were investigated. Besides, composition, structure and phase analysis studies were carried out, and the growth mechanism of BCZT multipods was proposed. It was found that the precursor's concentrations and dwell time in hydrothermal reactions play a critical role in the formation of BCZT multipods, and the desirable BCZT phase was obtained in samples using low barium and calcium concentrations and at a short reaction time. This research has general validity and can be extended to design more complex perovskite oxides.