| To obtain fundamental informations for ultrafine molybdenum powders, the preparatio of molybdenum powders by vapour phase reaction procedures of MoCl_5 with H₂ has been carried out in the temperature range of 500-900℃. The effects of reaction conditions on the reaction rate, specific surface area, particle size and morphology of ultrafine molybdenum powders were investigated by utilizing conductivity meter, BET method, X-ray diffraction, SEM and TEM techniques, respectively. It is apparent that the reaction rate and specific surface area were increased with increasing reaction temperature, H₂ and MoCl_5 gas partial pressure. The size and shape of the reaction products were nearly about 20-30㎚ and spherical, respectively. Especially, the first generated particles were agglomerated each other in chain type. |
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