Formation of aluminum nitride from metal–organic precursors synthesized by reacting aluminum tri-chloride with bis(trimethylsilyl)carbodiimide

Abstract

Metal–organic precursor for aluminum nitride (AlN) ceramics was synthesized by reacting aluminum tri-chloride (AlCl3) with bis(trimethylsilyl)carbodiimide (BTSC). Fourier transform infra-red (FT-IR) spectrum of the synthesized precursor exhibited characteristic absorption bands assigned to the carbodiimide (N=C=N) group at 2150–2250, and 851 cm−1, while the solid state 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectrum of the precursor exhibited single signal at 103 ppm which was thought to correspond to Al(N=C=N)4 unit. To examine the potential as a precursor for AlN ceramics, the intrinsic thermal conversion behavior up to 1800°C of the synthesized precursor was investigated under argon atmosphere. X-ray diffraction analysis revealed that the crystallization of AlN was found to start above 800°C, and fully crystallized AlN ceramics was synthesized by the additional heat treatment at 1800°C. In addition to the FT-IR and NMR spectroscopic analyses for studying the synthetic parameters such as reaction temperature and use of catalyst for the formation of polymeric precursors derived from AlCl3 and BTSC, the effects of heat treatment condition on the polymer/ceramics conversion yield, impurity and crystallinity of the AlN ceramics have been studied by using a thermogravimetric analyzer coupled with a quadrupole mass spectrometer (TG-MS). The results were discussed from a viewpoint to develop a novel synthesis method for AlN ceramics through the polymer precursor route.