STUDY OF CORROSION-PROTECTED AIN SAMPLES BY X-RAY PHOTOELECTRON-SPECTROSCOPY AND DIFFUSE-REFLECTANCE IR FOURIER-TRANSFORM SPECTROSCOPY

The surface composition of AIN samples exposed to atmospheric air has been studied by X-ray photoelectron spectroscopy (XPS) and diffuse ref lectance IR Fourier transform spectroscopy (DRIFTS) as a function of t heir preparation method. AIN samples have been obtained either by dire ct reaction of NH3 with Al2O3 at 1300 degrees C or by nitridation of a luminium metal with N-2 in the presence of CaCO3 at lower temperatures . The addition of CaCO3 leads to the formation of a CaCO3 thin layer a t the surface of the nitride particles that both inhibits the atmosphe ric corrosion and favours the sintering of the nitride powder.