Humidity sensing properties of (Ba, Sr) TiO_3 thin films grown by hydrothermal-electrochmical method

摘要

Thin films of (Ba, Sr) TiO_3 ceramic have been grown on Ti electrodes in aqueous solution of (Ba, Sr) (OH)_2 by hydroghermal- electrochemical method. These films are porous in nature and adsorb the water vapor when exposed to humid environment. X-ray diffraction data of as grown films shows the presence of four different peaks corresponding to barium strontium titanate. (BST) the scanning electron microscopy (SEM) shows a uniform distribution of spherical crystallites. Impedance measurements have been made at various frequencies and at different humidity levels to distinguish individual contributions to electrical conditions, arising from different sources like bulk and gain boundaries, inter granular contact regions and electrode-sample interface regions on the basis of non-Debye theory.