Metalorganic precursor for aluminum nitride (AlN) ceramics was synthesized by reacting aluminum tri-chloride (AlCl 3 ) 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 21502250, and 851 cm ¹1, while the solid state 27 Al 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 AlCl 3 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.

The luminescence properties related to the thermal polymer/ceramic conversion behavior of silicon dicarbodiimide {SDC, [Si(N=C=N) 2 ] n } have been investigated. SDC was synthesized by the non-oxidic solgel condensation reaction of silicon tetrachloride with bis(trimethylsilyl)carbodiimide. As-synthesized SDC showed no luminescence under UV light, while heat-treated SDC showed an appreciable photoluminescence (PL) and the maximum visible PL emission intensity was achieved by heat treatment at 400°C. Even after the heat treatment up to 970°C, the SDC preserved most of the N=C=N groups to keep whitish gray color without distinct free carbon formation, and emitted visible blue luminescence. The 400°C-heat treated SDC exhibited the intense luminescence excited at 281 and 379 nm wavelengths, while there was no PL emission excited by the N=C=N groupderived host absorption at 214 nm. The PL properties of the heat-treated SDCs could be correlated with their preservation of the local structure including N=C=N groups and defects formation during the heat treatment. Moreover, Eu 3+ -modified SDC was prepared by the same solgel method using Eu(III) chloride as the Eu 3+ -source. The results of Si NMR spectroscopic analyses revealed a complex formation between the Eu(III) chloride and bis(trimethylsilyl)carbodiimide. As a result, the Eu 3+ -modified SDC exhibited a characteristic PL red emission at around 600 nm attributed to the f-f-transition of Eu .