ANALYZING BaSrTiO₃ GAS SENSOR PROPERTIES UNDER NO₂ EXPOSURE: THE IMPACT OF IMPEDANCE SPECTROSCOPY

Impedance spectroscopy is an appropriate technique for studying the complexity of materials, in which their different frequency relationships can be exploited in such a manner that they can be efficiently separated. Barium strontium titanate BaSrTiO₃ (BST) is a ferroelectric material with unique properties that make it useful in a range of electronic applications. BST plays an important role in the field of gas-sensing applications. The potential application of BST material as a gas sensor for detecting nitrogen dioxide (NO₂) in the atmosphere was studied. Impedance spectroscopy studies were conducted across a wide frequency range from 10⁻¹ to 10⁶ Hz, in the temperature range of 100^◦C to 350^◦C and a relative humidity of 50%, and both in air and the presence of NO₂ in concentrations from 0.5 to 5 ppm. The results of the impedance analysis indicate that the broadband models, which comprise both single and parallel RC elements, can accurately represent the NO₂ gas interaction mechanism with the gas-sensitive layer of the BST material. These models were found to effectively capture changes in parameters associated with the interaction.