The large number of unusual processes taking place on the surfaces of refractory phases (chemical adsorption, catalysis, etc.), as well as the creation of technologically important films and coatings, gave rise to a great deal of interest in the experimental and theoretical studies of such surfaces. Their unusual properties are caused by the specific pecularities of surface electronic states and a number of elaborate experimental techniques and theoretical approaches have been developed for investigation of their geometrical and electronic structures.

In this chapter we present a review of experimental and theoretical studies of the chemical bonding and electronic structure of surfaces and layered systems formed from refractory carbides and nitrides of d-metals.

Surface states of carbides and nitrides as investigated by the electron and Auger spectroscopy methods

From the large number of experimental methods employed currently in the analysis of surfaces (see, e.g., Morrison (1977) and Blakely (1975)), X-ray electron spectroscopy (XES), angle-resolved photoelectron spectroscopy (ARPES) and Auger electron spectroscopy (AES) are the ones which are most widely used for the study of the electronic states of the external layers of refractory phases. Their basic ideas and technical details are described in a number of monographs, see for example Nemoshkalenko et al (1976), Gallon (1981) and Briggs and Sinha (1987).

Extensive studies of the surface electronic structure for binary 3d−5d-metal carbides and nitrides has been performed using XES, ARPES and AES methods (see the list of references to this chapter). ARPES of the (100) surface of TiC, for example, have been obtained by Callenas et al (1983) using Hei and Nei excitation.