New Solid State Sensor for Detection of Humidity, Based on Ni, Co, and Mn Oxide Nano Composite Doped with Lithium

• Main Authors: A. Kazemzadeh, F. A. Hessary, N. Jafari
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2008-07-01
• Series: Sensors & Transducers
• Subjects: NanoComposite; Solid State; Synthesis; Humidity Sensor; Element and Nano Technology
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/july_08/P_306.pdf

The lithium doped metal oxide nano composite was fabricated by sol-gel method. The metal oxide nano composite was then sintered at 700 °C for 6 h. The metal oxide nano composite was characterized by solid-state electrical measurement, AAS, XRD, fr-IR, SEM, BET, AFM and TEM studies to analyze activation energy for conduction, surface morphology and pore structure of the sensor materials, respectively. The humidity sensing properties of metal oxide nano composite was measured by employing the sensor configuration of a cylindrical disk. The micropores of nano composite have a crucial role in humidity sensing. The materials was subjected to water vapor of different humidity achieve by various water buffers at room temperature and the electrical conductivity was measured as a function of relative humidity (RT). The electrical resistively drastically decreases with increase in humidity and hence proving the materials to be a good water vapor sensor. The sensitivity factor (Sf) of Li doped metal oxide nano composite has been increased 9.2 times as compare to the undoped metal oxide nano composite sensitivity factor. The response and recovery time of sensor was also measured.