Dendritic crystals of α‐MoO ₃

Abstract 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 ( 99m Tc) through neutron irradiation. In the present work, the synthesis of α‐MoO 3 dendritic crystals was achieved by thermally evaporating α‐MoO 3 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‐MoO 3 through X‐ray diffraction. α‐MoO 3 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‐MoO 3 dendrites and investigating their growth mechanisms.