Material characterization of sputtered sodium-ion conductive ceramics for a prototype CO2 micro-sensor

RF magnetron sputtered Nasicon and sodium carbonate ionic conductive thin films (2000 Angstrom) have been characterized using physical-chemical methods such as Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). It is found that the overall chemical composition of sputtered and of laser deposited films is similar to that of the sputtering target. The Nasicon films show a sufficiently high ionic conductivity (0.36 S cm(-1) at 360 degrees C) for use in a prototype integrated CO2 sensor with the dimensions of 3 x 4 mm.