Study of carbon dioxide sensing characteristics of nanocrystalline barium titanate

Abstract

Barium titanate ceramic is a highly significant ferroelectric material with widespread usage in the electronic industries, particularly in the production of multi-layer ceramic capacitors (MLCC). As electronic devices continue to shrink in size, the influence of size on the dielectric properties of BaTiO3 perovskite has gained remarkable importance. The ongoing trend of miniaturization has sparked interest in exploring the functional properties of this material at the nano-scale. Among the various methods available, mechanical milling stands out as the simplest and most cost-effective technique for obtaining nanostructured materials from bulk sources. High-energy ball milling has proven effective in producing nanocrystalline BaTiO3 perovskite, inducing structural relaxation in surface atoms and generating inhomogeneous strain through the introduction of defects in crystalline solids. These defects play a crucial role in influencing the properties of the resulting powder. Notably, the presence of defects leads to a reaction between the nanostructured BaTiO3 and atmospheric carbon dioxide, resulting in the formation of BaCO3. This project focuses on investigating the carbon dioxide sensing characteristics of nanocrystalline BaTiO3, utilizing the effects of CO2 on the structural and dielectric properties of this material. Several techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and impedance spectrometry, have been employed to assess changes in the structure and dielectric measurements and establish correlations with the gas sensing characteristics. The ultimate goal of this study is to explore the practical applications of nanocrystalline BaTiO3 in CO2 gas sensors. By investigating the distinct properties of nanocrystalline BaTiO3, this research could offer valuable insights to explore its possible applications in various sensing devices, such as laser in-process sensing, laser safety, and optoelectronic devices due to its ferroelectric, piezoelectric, and photorefractive properties.