Positron annihilation study for cadmium (electronic structure and enhancement effect)

• Authors: A. Hamid
• Languages of publication: EN

Abstracts

EN

The three dimensional electron density in momentum space ρ(p) and in wave vector space n(k) was reconstructed for cadmium (Cd). The measurements were performed using the two dimensional angular correlation of annihilation radiation (2D-ACAR) technique. Enhanced contributions in the spectra were observed around 5.5 mrad, discussed in terms of a Kahana-like enhancement effect. From another viewpoint, Fermi radii were analyzed in the (λM K), (ALM) and (AHK) planes, and they showed a maximum deviation of about 4% from the free electron Fermi radius. Moreover, comparisons to a radio-frequency size effect (RFSE) experiment and theoretical band structure calculations (using augmented plane wave (APW), linear combination of atomic orbital (LCAO) and linear muffin tin orbital (LMTO) methods) were examined. The results showed a qualitative agreement with both APW and LCAO calculations. However, a favorable agreement with the APW method was determined via Fermi surface dimensions. The differences of bands' occupation of n(k) between the current work and the APW method were argued in view of positron wave function in Cd.

Keywords

EN

Kahana-like enhancement effect; electronic structure; two-dimensional angular correlation of annihilation radiation (2D-ACAR); Fermi surface; reciprocal lattice points; electron densities in momentum space; 71.20.-b

• Publisher: De Gruyter Open
• Journal: Open Physics
• Year: 2003
• Volume: 1
• Issue: 4
• Pages: 655-668

Dates

published

1 - 12 - 2003

online

1 - 12 - 2003

Contributors

author

A. Hamid

• Department of Physics, Faculty of Science, Helwan University, 11795, Cairo, Egypt

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Identifiers

DOI

10.2478/BF02475909