Preparation of chemical precursors to aluminum nitride from an ambient-temperature chloroaluminate ionic liquid

摘要

Heptachlorodialuminate (Al_2Cl_7~-) from an acidic ambient temperature ionic liquid was used to prepare precursors to aluminum nitride (AlN). The ionic liquid was a 2:1 mole ratio mixture of aluminum chloride (AlCl_3) and trimethylphenylammonium chloride (TMPAC). Al_2Cl_7~- reacted exothermically with the bases ammonia (NH_3) and hydrazine (N_2H_4) to form bulk quantities of precursors to AlN. Reaction of NH_3 with the molten salt produced a mixture of ammoniate complexes, AlCl_3(NH_3)_(1-3). Reaction with N_2H_4 produced polymers. The ammoniate was characterized by elemental analysis and FTIR spectroscopy. This precursor was used to prepared thin films of AlN by chemical vapor deposition. The films were characterized by x-ray diffraction. Auger Electron Spectroscopy and Scanning Electron Microscopy. The approach reported here demonstrates a new route to production ceramic nitride materials by exploiting highly reactive chemistry in a chloroaluminate ionic liquid.