The employ of manganese oxide to improve the selectivity of gas sensitive SnO$_x$ films

To improve the selectivity of gas-sensitive SnO$_x$ films, SnO$_x$/MnO$_y$ composite structures were obtained in which manganese oxide plays the role of a NO$_2$ sorbing filter. The microstructure and chemical composition of the films were characterized using scanning electron microscopy and X-ray photoelectron spectroscopy. The structures were tested to detect 5 ppm NO$_2$ at room temperature. The sensory response of SnO$_x$ films in the presence of NO$_2$ decreases by 16 times after coating the MnO$_y$ filter layer.