Effect of Synthesis Process on The Piezoelectric Properties of (1-x) NBT-xBT: A Comparative Study Between Solid State and Hydrothermal Methods

Abstract

Lead-free oxide perovskite materials are produced to ensure that no toxic or dangerous waste is released into the environment, although this technique often requires a high-temperature synthesis method. Nevertheless, the development of an environmentally friendly chemical process to carry out the synthesis of perovskite material in the laboratory at low temperature is a major challenge. In this investigation, to lower the temperature of the thermal treatment, (1-x)(Na0.5Bi0.5)TiO3-xBaTiO3 (abbreviated as (1-x)NBT-xBT) ceramics were synthesized using two different methods: a hydrothermal method and a conventional calcination process (solid-state), using the same reagents. The effects of various synthesis techniques on the composition, structure, morphology, and dielectric properties of the (1-x)NBT-xBT ceramics were registered and examined. The XRD plots taken at ambient temperature were used to verify the phase formation of the samples. The occurrence of functional bands was also verified by Raman spectroscopy at ambient temperature. Using the Rietveld refinement method were able to detect the morphotropic phase boundary (MPB) near x=0.05-0.07. When the hydrothermal process was adopted, the (1-x)NBT-xBT ceramics show a single perovskite structure sintered at 1000°C. Moreover, scanning Electron Microscopy (SEM) examination revealed a uniform distribution of grains and a significant change in grain size with the increase in BaTiO3 concentration when compared to the conventional method. The microstructure of ceramics is generally strongly influenced by the method used to prepare the powders, which has a considerable impact on their performance. Piezoelectric and dielectric properties of the specimens have been compared with the properties of those prepared by the hydrothermal process. Thus, the choice of the suitable synthesis method depends on the desired properties of the (1-x)NBT-xBT materials.