Abstract
Abstract Thick films of pure Cr 2 O 3 were prepared by screen-printing technique. Pure chromium oxide (Cr 2 O 3 ) thick films were almost insensitive to reducing gases. The surfaces of these films were modified by dipping them into a 0.01 M aqueous solution of ferric chloride (FeCl 3 ) for different intervals of time, followed by firing at 550 °C for 30 min. The firing resulted in the oxidation of the FeCl 3 additive into Fe 2 O 3 . The characterizations and the gas sensing properties of pure and surface activated Cr 2 O 3 thick films were investigated. The grains of Fe 2 O 3 dispersed around the grains of Cr 2 O 3 varied the barrier height between the grains. Upon exposure to reducing gases at a particular temperature, the barrier height decreased greatly, leading to a drastic increase in conductance. The sensor gave optimum responses to different gases at different operating temperatures. The surface misfits, calcination temperature and operating temperature can affect the microstructure and gas sensing performance of the sensor. The quick response and fast recovery are the main features of this sensor. The effects of microstructure and activator concentration on the gas response, selectivity, response time and recovery time of the sensor in the presence of reducing gases were studied and discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
