On the Preparation of the Nitrides of Aluminum and Gallium

The n i t r ides of a luminum and ga l l ium have been the object of recent invest igat ions deal ing wi th thei r electr ical, optical, and other proper t ies (1-6). Some s imple methods of p reparat ion of these compounds are descr ibed here. Aluminum n i t r ide.-- I f a fine powder of a luminum phosphide is f ired for 1-2 hr at 1000~176 in a slow s t ream of d ry ammonia phosphorus evolves which condenses downst ream and the theoret ica l weight of a luminum n i t r ide is obta ined: 1 3 A lP + NH~-- A1N + ~-P ~ + ~-H,., The white to l ight gray powder so prepared is not, however, wel l c rysta l l i zed and only after overn ight f ir ing at 1100 ~ gives sharp x- ray di f fract ion pat-