Positron annihilation in vacancies: Korringa-Kohn-Rostoker formulation and application to Cu

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Physical Review (Section) B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.40.8620· OSTI ID:5217408

Prasad, R; Benedek, R; Robinson, J E ^[1]; Bansil, A ^[2]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (USA)
2. Department of Physics, Northeastern University, Boston, Massachusetts (USA) 02115

We develop a Green's-function formulation of the two-photon momentum density {rho}{sub 2{gamma}}({bold p}) for a vacancy-trapped positron in a metal within the framework of the Korringa-Kohn-Rostoker (KKR) scheme. This formulation is easily extended to treat disordered alloys. Employing a real-space representation for the electron and positron Green's functions, we express {rho}{sub 2{gamma}}({bold p}) as a lattice sum, which converges rapidly for a vacancy-trapped positron. Results for a vacancy in Cu are presented; these are the first calculations of {rho}{sub 2{gamma}}({bold p}) for a vacancy in a {ital d}-band metal. It is found that {rho}{sub 2{gamma}}({bold p}) in the region {ital p}{approx lt}4 mrad is dominated by contributions from the vacancy and the nearest-neighbor (NN) shell. Our considerations indicate that the width and weight of the central peak in {rho}{sub 2{gamma}}({bold p}) is a sensitive function of the NN-shell composition in metals and alloys.

• OSTI ID: 5217408
• Journal Information: Physical Review (Section) B: Condensed Matter; (USA), Journal Name: Physical Review (Section) B: Condensed Matter; (USA) Vol. 40:13; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BAND THEORY
BASIC INTERACTIONS
COPPER
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC INTERACTIONS
ELECTRONIC STRUCTURE
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FUNCTIONS
GREEN FUNCTION
INTERACTIONS
LEPTONS
METALS
POINT DEFECTS
POSITRONS
TRANSITION ELEMENTS
TRAPPING
VACANCIES