Reaction study of aluminium chloride with ammonia and mechanisms leading to aluminium nitride

The compound formed between AlCl 3 and NH 3 at room temperature and low temperature, characterized by different analysis methods, corresponds to the formula AlCl 3 · 6NH 3. This intermediate was heated to 900 °C under an ammonia stream to obtain aluminium nitride in low yield; as by-product NH 4Cl was formed during the thermolysis. In order to explain the decomposition mechanisms, two new pyrolysis were realized, under nitrogen and under reduced pressure. These showed formation of Al(NH 2)NH in addition to NH 4Cl during the thermal decomposition. Al(NH 2)NH can react with HCl, which results from the dissociation of NH 4Cl, to form AlClNH volatile combination. This is carried out by the gaseous stream during the thermolysis, thereby accounting for the low synthesis yield.