IMPERFECTIONS IN SOLIDS.

The report describes investigations into several different aspects of the electronic structure of defects in solids. The effect of electronic polarization on the optical properties of insulators and some characteristics of the absorption bands in KCl are considered. A brief discussion of an experiment on the optical transmission properties of plastically deformed germanium is given. The bulk of the study is concerned with electron scattering from vacancies and solute atoms. This scattering is responsible for many of the properties of alloys and is investigated here through residual resistivity, the Kondo effect which includes spin scattering, and electric field gradients in alloys. The effect on the residual resistivity of the Brillouin zone boundaries intersecting the Fermi surface is investigated and found to be very important, changing the theoretical value of the resistivity by a factor of 2 to 3 and bringing theory into agreement with experiment. Work on the band structure of bismuth and on the elastic constants of aluminum and lead is also mentioned. Author