Fabrication of Nanocomposites of SnO2 and MgAl^sub 2^O^sub 4^ for Gas Sensing Applications

Issue Title: Special Section: 2015 Electronic Materials Conference. Guest Editors: Joshua Caldwell, Joshua Zide, Suzanne Mohney, Jamie Phillips, F. Shadi Shahedipour-Sandvik, Nadeem Mahadik, Fareed Qhalid, Suchi Guha, Rachel Goldman, Jian Xu, Angel Yanguas-Gil, Ganesh Balakrishnan Simple solid-state and sol-gel routes have been used to synthesize nanocomposites of tin oxide and magnesium aluminate at calcination temperature of 900 K for gas sensing applications. The effects of the surface structure of magnesium aluminate on the gas response for different concentrations of tin oxide addition were investigated for potential use in gas sensors. (SnO2)x doped in small amounts x into magnesium aluminate resulted in three nanocomposite samples MAS0.25, MAS0.50, and MAS0.75 for x = 0.25, 0.50, and 0.75, respectively, plus MgAl^sub 2^O^sub 4^ (MA) for x = 0. The response to different pressures of gases such as oxygen (O2), carbon monoxide (CO), and ethanol (C^sub 2^H^sub 5^OH) was quantitatively analyzed for all samples at different operating temperatures. The temperature was varied linearly by increasing the supply to a heating pad mounted below the sensor sample, regardless of the gas pressure inside the chamber. All the sample materials showed good response at different gas pressures (1 bar to 2 bar) and operating temperatures (300 K to 600 K). It was noted that the composite samples showed enhanced and fast response to gases, at both lower and higher operating temperatures, with detection of even the smallest change in gas pressure.