Crystalline and microstructure study of the AlN-Al2O3 section in the Al-N-O system. II. phi '- and delta-AlON spinel phases

Results from the crystalline and microstructure study of the phi'- and delt a-AlON spinel phases by X-ray diffraction, neutron diffraction and standard -resolution transmission electron microscopy techniques are reported. Sever al samples having different compositions in mol % AlN were considered. A st ructural model is proposed to account for the double modulation of composit ion and displacement of the cations and anions, which has been determined f or these two phases and for the relationship with the gamma-AlON spinel pha se. Some high-resolution transmission electron microscopy experiments have confirmed the present structural model. A discussion with reference to prev ious data is presented.