Positron annihilation in alloys

1977 ◽  
Vol 55 (15) ◽  
pp. 1335-1341 ◽  
Author(s):  
K. M. Hong ◽  
J. P. Carbotte
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Coherent Potential Approximation ◽  
Fermi Momentum ◽  
Photon Momentum ◽  
Numerical Computations ◽  
Potential Approximation ◽  
Momentum Distributions ◽  
Annihilation Photon

A coherent potential approximation (CPA) treatment of positron annihilation in an alloy is presented. Simple formulae for the spatial and the momentum distributions of the positrons are derived. Numerical computations are performed to illustrate the effects of the smearing of the positron momentum distribution and of the electron Fermi momentum of the annihilation photon momentum distribution.

MOMENTUM DISTRIBUTION OF METALLIC ELECTRONS BY POSITRON ANNIHILATION

1957 ◽  
Vol 35 (2) ◽  
pp. 168-183 ◽  
Author(s):  
A. T. Stewart
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Center Of Mass ◽  
Velocity Dependence ◽  
Conduction Electrons ◽  
Two Photon ◽  
Photon Decay ◽  
Electron Positron ◽  
Momentum Distributions ◽  
Annihilation Probability

The angular correlation of photons from the two-photon decay of positrons has been measured for positrons annihilating in some 34 elements, mostly metals. These data give the momentum distribution of photons and hence of the center of mass of the annihilating electron–positron pairs. The momentum distributions are discussed in terms of the velocity dependence of the annihilation probability. It is concluded that the observed momentum distributions are primarily the momentum distributions of the conduction electrons in the metals. A higher momentum component is observed, which is attributed to ion core effects.

Defect Characterization in Thermoelectric Zn-Sb Systems by Positron Annihilation

2017 ◽  
Vol 373 ◽  
pp. 245-248
Author(s):  
Ting Zhang ◽  
Kai Zhou ◽  
Zhi Quan Chen
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Defect Characterization ◽  
Doppler Broadening ◽  
Lifetime Measurements ◽  
Electron Positron ◽  
Momentum Distributions ◽  
Positron Lifetimes ◽  
Doppler Broadening Spectra ◽  
Coincidence Doppler Broadening

Positron lifetimes and momentum distributions of annihilating electron-positron pairs have been calculated for vacancies in ZnSb and Zn4Sb3. The calculated positron lifetimes for bulk ZnSb and Zn4Sb3 are 203 ps and 208 ps, and for VZn in ZnSb and Zn4Sb3 are 249 ps and 237 ps respectively. The calculated momentum distribution results indicate the VZn in both ZnSb and Zn4Sb3 has less characterization from elemental Zn. Using coincidence Doppler broadening spectra combined with lifetime measurements can reveal the vacancy structure in ZnSb and Zn4Sb3.

Fully relativistic calculation of the two-photon momentum distribution for positron annihilation in tungsten

1991 ◽  
Vol 43 (9) ◽  
pp. 6996-7002 ◽  
Author(s):  
G. J. Rozing ◽  
P. E. Mijnarends ◽  
R. Benedek
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Photon Momentum ◽  
Two Photon ◽  
Relativistic Calculation

Generalized augmented-space theorem for correlated disorder and the cluster-coherent-potential approximation

1993 ◽  
Vol 48 (24) ◽  
pp. 17724-17731 ◽  
Author(s):  
Abhijit Mookerjee ◽  
Rajendra Prasad
Keyword(s):  
Coherent Potential Approximation ◽  
Potential Approximation ◽  
Augmented Space

Electronic structure calculations on alloys using the polymorphous coherent-potential approximation

2004 ◽  
Vol 70 (6) ◽  
Author(s):  
S. Pella ◽  
J. S. Faulkner ◽  
G. Malcolm Stocks ◽  
Balazs Ujfalussy
Keyword(s):  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
Coherent Potential Approximation ◽  
Potential Approximation ◽  
Structure Calculations

Analytic Properties of the Homomorphic Cluster Coherent Potential Approximation

1979 ◽  
Vol 47 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Takashi Odagaki ◽  
Fumiko Yonezawa
Keyword(s):  
Coherent Potential Approximation ◽  
Potential Approximation

Electronic States of a Liquid Metal from the Coherent-Potential Approximation

1970 ◽  
Vol 1 (2) ◽  
pp. 934-936 ◽  
Author(s):  
J. S. Faulkner
Keyword(s):  
Liquid Metal ◽  
Electronic States ◽  
Coherent Potential Approximation ◽  
Potential Approximation
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