Synthesis, fabrication and characterization of CaMgFe_xTi_yO₁₂-based electro-ceramics sensor

The present study aims to fabricate a novel multiphase ceramic-nanocomposite having giant dielectric constant and minimum dielectric loss. Under a high palletization pressure along with novel step-sintering has played a vital role to improve the porosity, reduce the density and grain-boundary resistance leading to enhanced dielectric characteristics. The formation of different phases in developed nanocomposite is evaluated by XRD analysis. Frequency-dependent impedance spectroscopy of developed electro-ceramic reveals the better impedance, electrical modulus, dielectric permittivity (ε′), loss-tangent (tanδ), and water physisorption capacity compared to unsintered compound and other existing ceramic compounds. The developed sensor exhibits high sensitivity up to 0.27 MΩ/Δ% RH, fast response (19.37 s) and recovery time (39.17 s) as well as low hysteresis of ~ 3.31% (for the impedance) and ~ 3.29% (for capacitive) at 100 Hz. Therefore, the developed nano-electronic ceramic seems to be a very promising material for manufacturing high-efficiency humidity sensors.