ELECTRONIC SPECTRA OF ORDERED AND DISORDERED SYSTEMS

Abstract

The work reported in this thesis is the result of the author's attempts to investigate the nature of electron states in disordered alloys. In particular, the interest was in alloys of the noble metals. It was clear that two aspects of the problem must be explored. 1) The choice of the one-electron potential and 2) The scheme for determining eigenvalues. Both these choices must be such that for the corresponding pure host, they give an adequate description of the band structure. The first part of the thesis is therefore concerned with an energy-band calculation of silver and its change with different choices of the crystal potential. The 2nd chapter is devoted to an exposition of one of the methods of energy band calculation of metals, namely the Green's function method of Korringa, Kohn and Rostoker (also called the KKR method), and its comparison with other methods. The reasons for the choice of the KKR method for this investigation :Ire also indicated. The 3rd chapter gives details of methods of constructing the crystal Potentials and some other details relevant to the calculation. The IVth chapter deals with the application of the method to calculate the energy bands in silver and presents the conclusions regarding the choice of a crystal potential