Accession Number : AD0261360

Title :   IMPURITIES AND IMPERFECTIONS IN METALS AND SEMICONDUCTORS

Corporate Author : SHEFFIELD UNIV (ENGLAND)

Personal Author(s) : MARCH,N.H. ; MURRAY,A.M.

Report Date : 31 MAY 1961

Pagination or Media Count : 1

Abstract : IT IS SHOWN HOW A FULL PERTURBATION TREATMENT OF THE Dirac density matrix may be developed as a basis for self-co sistent calculations in free-el ctron metals containing localized efects. The present pert rbation series is shown o sum o the well-known result for the case of slowly varying potentials. The application of the present approach to Bloch wave functions rather than plane waves is briefly considered. Friedel's generalized firstorder method, applicable to a band structure, may be obtai ed from the present theory for sufficiently slowly varying potentials. Two specific applications of the theory are made. The first concerns perturbations in a gas of density appropriate to metals, at low temperatures, and the second is to the problem of ionized impurity scattering. Some approximations are considered transcending first-order perturbation theory, with particular reference to positron lifetimes in met ls. An explicit attempt to evaluate the second-order perturbation correction for both attractive and repulsive potentials is reported. (Author)

Descriptors :   *METALS, *PERTURBATION THEORY, *SEMICONDUCTORS, DENSITY, GAS IONIZATION, IMPURITIES, INTEGRAL EQUATIONS, INTEGRAL TRANSFORMS, IONIZATION, OSCILLATION, PARTIAL DIFFERENTIAL EQUATIONS, TEMPERATURE, THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE