Neutron diffraction study of the ordered structures of nonstoichiometric titanium carbide

Abstract The ordered structures and phase transitions in TiC 0.62 and TiC 0.59 are investigated on the high resolution neutron diffractometer. It is established, that low-temperature trigonal δ″(sp.gr. R 3 m or sp.gr. P3 1 21) and high-temperature cubic δ′(sp.gr. Fd3m) ordered structures, according to the temperature, exist in the investigated carbide samples. Under heating, the sample TiC 0.62 experiences the order-order (δ″( R 3 m )→δ′(Fd3m)) phase transition at 770°C and then, the order-disorder ((δ′(Fd3m)→δ(Fm3m)) phase transition at 790°C.