Symmetry analysis of ordered phases of the lower tungsten carbide W2C

The channels of disorder-order phase transitions through which there can arise orthorhombic (space group Pbcn) β′-W₂C, rhombohedral (space group P $ \bar 3 $ \bar 3 m1)β″-W₂C, and trigonal (space group P $ \bar 3 $ \bar 3 1m)ɛ-W₂C superstructures of the disordered lower hexagonal carbide β-W₂C have been determined. The distribution functions of carbon atoms in the superstructures under consideration have been calculated, and the physically admissible sequence of transformations associated with the ordering of the lower carbide β-W₂C that occur with a decrease in the temperature has been established.