oxide ceramic (and other non-oxide ceramic materials or semiconductors) in vacuo in high temperature environments. Under this respect to underline the concept of evaporation and condensation coefficients is of concern. In studying vaporization reactions, a pressure-composition diagram (P-x) is useful for representing occurrences in a thermodynamically effusing system. Laser- induced vaporization extends the ranges of pressure and temperature and allows information on the materials behaviour near the critical regions to be obtained. Historically, investigation of the vaporization behavior of polycrystalline and also single-crystal materials, in congruent and non-congruent mode, represented a typical and focal topic in HTMC research. Selected examples of vaporization processes of simple substances of historical relevance (like the vaporization of carbon to monoatomic and polyatomic species and clusters; of alumina, etc. as anticipated in Topic 3 above) may be illustrated. It is useful to underline that usually the identification and characterization of gaseous “high-temperature species” is made through the study of vaporization processes. This topic should be presented to students in parallel with the experimental techniques presented separately in this syllabus (see section 5.2).
Among the numerous contributions on this subject appeared in contributed books,
proceedings volumes, and review papers the following bibliographic references have been
Stolyarova and G. Semenov, “Mass spectrometric study of the evaporation of oxide systems”, Wiley, 1994 ;
Kubaschewski, C.B. Alcock, P.J. Spencer, "Materials Thermochemistry", 6th edition revised of "Metallurgical Thermochemistry", Pergamon Press, Oxford/New York, 1993
M. Rosenblatt “Evaporation from solids” in N.B. Hannay, editor, "Treatise on Solid State Chemistry", Plenum Press, New York / London, vol.6A, chapter 3, 1976;
Rapp, editor, Physicochemical measurements in metals research, Vol IV, Part 1 of Techniques of metal research, Wiley Interscience, 1970, Chapters 1 to 5