Simultaneous tuning of the phase transition temperature and infrared optical properties of Mo-doped VO2 powders for intelligent infrared stealth materials

The development of an intelligent infrared camouflage material whose infrared emissivity can actively adapt to environmental changes is a key frontier in the field of infrared stealth. In this study, Mo-doped VO2 powder was prepared via a hydrothermal method, which led to an intelligent infrared camouflage material whose infrared radiation characteristic can adaptively change with the environmental temperature. The samples were characterized by XRD, SEM, DSC, FTIR and infrared thermal imaging. Combined with the results of the first-principles calculation, the coupling effect mechanism of Mo6+ doping concentration on the phase transition temperature and infrared photoelectric properties of VO2 material was systematically analyzed. The results showed that Mo6+ impurities had significant effects on the structure, morphology, composition, phase transition temperature and infrared reflectivity of VO2 powder. The doping process effectively reduced the phase transition temperature of VO2 and expanded the change range of infrared emissivity (△ε) before and after the metal-to-insulator (MIT) transition. With the increasing amount of Mo6+ doping, the infrared reflectance of VO2(M) gradually decreased at low temperatures, while the infrared reflectance of VO2(R) increased at high temperatures. The MIT transition temperature of Mo-doped VO2 versus undoped VO2 reduced to 31.5 °C, and the △ε increased by 153%, this is expected to meet the performance requirements of intelligent infrared stealth materials.