High-pressure phases in nanocrystalline Co(C) films obtained by pulsed plasma vaporization

The phase composition of nanocrystalline Co(C) films obtained by a new puls ed plasma vaporization technique was found by studying their atomic structu re and magnetic properties. The films deposited at the substrate temperatur e T = 50 degreesC were of heterophase structure and consisted of a supersat urated solid Co(C) solution and the metastable Co3C carbide. The films obta ined at T = 150 degreesC represented a mechanical mixture of the metastable Co3C and Co2C carbides. The metastable Co3C and Co2C carbides obtained in a nanocrystalline state were high-pressure phases (similar to 100 kbar). Th e thermal stability ranges of these metastable phases were determined. (C) 2000 MAIK "Nauka / Interperiodica".