Preparation of AlN from poly(ethyliminoalane) via pyrolysis

Aluminium nitride (AlN) powder has been prepared by pyrolysing poly(ethyliminoalane) under Ar (at 1600 °C for 2 h) and NH₃-N₂ (at 600 °C for 2 h under NH₃ and at 1350 °C for 8 h under N₂) atmospheres, and the products have been characterized by X-ray powder diffraction, solid-state ²⁷Al NMR spectroscopy, elemental analysis, scanning electron microscopy, and nitrogen adsorption measurement. The only crystalline product was AlN, in which carbon and oxygen were hardly present by solid-solution formation. A considerable amount (17.1 mass%) of carbon remained in the product pyrolysed under Ar, whereas most of carbon was removed during the pyrolysis under NH₃-N₂ (0.1 mass%). The AlN particles obtained by pyrolysis under NH₃-N₂ were finer than those obtained by pyrolysis under Ar. The ceramic yields were 50% (Ar) and 57% (NH₃-N₂); the latter value is close to the theoretical yield (58%).