Theoretical studies of the angular correlation of positron annihilation in germanium

A pseudopotential formalism is applied to calculate the angular correlation of positron annihilation radiations (ACPAR) along the (100), (110) and (111) directions in Ge. The results are found to agree very well with the measured data. Calculations show that the ACPAR line shapes, particularly in the low-momentum region, are very much influenced by the detailed nature of bonding. Two-photon autocorrelation functions corresponding to the above symmetry directions are also presented and some interesting conclusions are drawn regarding positron-electron many-body correlation effects.

[1]  B. K. Panda.  Studies of the Autocorrelation Functions in Aluminium , 1992 .

[2]  B. K. Panda,et al.  Positron Annihilation Angular Correlation Studies in GaSb , 1992 .

[3]  B. K. Panda,et al.  Theoretical Calculation of Positron Annihilation Angular Correlation Anisotropy in GaP , 1991 .

[4]  B. Johansson,et al.  Angular correlation distribution of electron-positron annihilation in graphite , 1991 .

[5]  B. Johansson,et al.  Two-dimensional electron momentum distribution of graphite , 1991 .

[6]  B. Johansson,et al.  A novel formalism for calculating positron annihilation characteristics , 1991 .

[7]  B. Johansson,et al.  Positron-electron product wavefunction calculation of angular correlation in silicon , 1991 .

[8]  G. Dlubek,et al.  ESTIMATION OF THE FERMI MOMENTUM IN AL FROM THE FOURIER TRANSFORM OF THE POSITRON ANNIHILATION ANGULAR CORRELATION CURVE , 1990 .

[9]  H. Aourag,et al.  Positron Distribution in Semiconductors , 1990 .

[10]  R. N. West,et al.  Positron Annihilation in Si and Ge , 1989 .

[11]  K. Shindō,et al.  Anisotropies of Compton profiles of tetrahedrally bonded semiconductors , 1984 .

[12]  J. Schneider,et al.  Identifying the bonding in diamond and silicon using compton scattering experiments , 1981 .

[13]  R. N. West,et al.  A high-efficiency two-dimensional angular correlation spectrometer for positron studies , 1981 .

[14]  P. E. Mijnarends,et al.  Point-geometry angular correlation curves for Cu: A study of enhancement in positron annihilation , 1979 .

[15]  J. Schneider,et al.  Structural information from directional compton profile measurements on Si and Ge , 1978 .

[16]  A. Bansil,et al.  Electronic Momentum Densities by Two-Dimensional Angular Correlation of Annihilation Radiation in Aluminum , 1976 .

[17]  James R. Chelikowsky,et al.  Nonlocal pseudopotential calculations for the electronic structure of eleven diamond and zinc-blende semiconductors , 1976 .

[18]  S. Berko,et al.  Positron annihilation in germanium , 1975 .

[19]  Marvin L. Cohen,et al.  Special Points in the Brillouin Zone , 1973 .

[20]  K. Fujiwara,et al.  An Examination of the Angular Correlation of Annihilation Radiation in Silicon Single Crystal , 1973 .

[21]  K. Fujiwara,et al.  ENHANCEMENT OF ANNIHILATION RATE OF ELECTRON--POSITRON PAIRS IN PERIODIC FIELDS. , 1972 .

[22]  D. Stroud,et al.  Assumption-Independent Single-Particle Wave Functions for Positrons in Solids: Applications to Angular Distributions in Al and Si , 1968 .

[23]  J. C. Erskine,et al.  Electron Momentum Distribution in Silicon and Germanium by Positron Annihilation , 1966 .