Vacancy distribution in ordered Me6-C5-type carbides

Abstract
By symmetry analysis of Me6C5 superstructures observed experimentally in carbides, the MeC0.83-Me6C5 order-disorder phase-transition channels have been determined. For the superstructures examined using the static-concentration-waves method, the distribution functions of carbon atoms have been calculated. It is shown that an Me6C5-type atomic ordering is described by several long-range order parameters. The regions of admissible values of the order parameters have been determined for each of the superstructures treated.