Data on order-disorder phase transformations in strongly nonstoichiometric carbides and nitrides MX_y (X=C, N) of Group IV and V transition metals at temperatures below 1300-1400 K are reviewed. The order-parameter functional method as applied to atomic and vacancy ordering in strongly nonstoichiometric MX_y compounds and to phase equilibrium calculations for M-X systems is discussed. Phase diagram calculations for the Ti-C, Zr-C, Hf-C, V-C, Nb-C, Ta-C, Ti-N, and Ti-B-C systems (with the inclusion of the ordering of nonstoichiometric carbides and nitrides) and those for pseudobinary carbide M⁽¹⁾C-M⁽²⁾C systems are presented. Heat capacity, electrical resistivity and magnetic susceptibility changes at reversible order-disorder phase transformations in nonstoichiometric carbides are considered.

PACS: 61.72.Ji, 64.60.Cn, 81.30.Dz (all) DOI: 10.1070/PU2000v043n01ABEH000647 URL: https://ufn.ru/en/articles/2000/1/a/ 000086055100001 Citation: Gusev A I "Order-disorder transformations and phase equilibria in strongly nonstoichiometric compounds" Phys. Usp. 43 1–37 (2000) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Оригинал: Гусев А И «Превращение беспорядок-порядок и фазовые равновесия в сильно нестехиометрических соединениях» УФН 170 3–40 (2000); DOI: 10.3367/UFNr.0170.200001a.0003