Effect of the Type of the Crystal Phase of In 2 O 3 On Its Conductivity and Sensor Properties in Hydrogen Detection

Indium oxide is synthesized hydrothermally from an aqueous or alcoholic solution of indium nitrate. The phase composition and structure of the synthesized samples, as well as their conductivity and sensory response during the detection of hydrogen, are studied. A change in the conditions of hydrothermal synthesis leads to the formation of a metastable rhombohedral phase together with the main cubic phase of indium oxide. It is shown that an increase in the concentration of the rhombohedral phase in indium oxide leads to an increase in its conductivity and the maximum sensor activity for hydrogen.