The structure and stability of tantallum nitrides

The results of tantalum nitrides inVestigation are generalized with help of neutAon diffraction. The samples for investigations are prepared by the method of self-propagating high-temperature synthesis (SHS). It is shown, that at the room temperature and atmospheric pressure the cubic and others tantalum nitrides with nitrogen content More than equiatomic compositiOn are non-equilibrium. They can be formed and exist in the fine films or in the near the subsurface layers. Some of them, can be probably prepared under extreme conditions, for exaMple by means of SHS, and in massive samples. But in all cases the exist in metastable state and they can be preserVed for a long time due to difficult or low diffusion mobility of atoms