Dendritic crystals of α-MoO3

The dendritic structure possesses a remarkably large surface area, which is advantageous for numerous chemical reactions and physical processes. Currently, we are seeking an appropriate molybdenum trioxide target for the production of the radionuclide technetium-99 m (^99mTc) through neutron irradiation. In the present work, the synthesis of α-MoO₃ dendritic crystals was achieved by thermally evaporating α-MoO₃ powders in a tube furnace under a flowing argon gas atmosphere at evaporation temperatures (T_E) ranging from 800°C to 1000°C. The scanning electron microscope results demonstrated the successful synthesis of dendrites. The dendrites exhibited their maximum dimension at a temperature of 900°C. The dendrites were identified as α-MoO₃ through X-ray diffraction. α-MoO₃ dendrites originated from the elevated temperature region on the upper surface of the tube. The temperature distribution measurements indicate that the formation of dendrites occurred after the transition from non-uniform to uniform growth. To the best of our knowledge, this is the first report on synthesizing α-MoO₃ dendrites and investigating their growth mechanisms.