VNU. JOURNAL OF SCIENCE, Mathematics - Physics, T.xXI, n02, 2005
Abstract:
Analytical expression for the Displacement-displacement Correlation
Function (DCF) CR has been derived based on the derived Mean Square Relative
Displacement (MSRD) σ2 and the Mean Square Displacement (MSD) u2 for fcc
crystals. The effective interaction potential of the system has been considered by
taking into account the influences of nearest atomic neighbors, and it contains the
Morse potential characterizing the interaction of each pair of atoms. Numerical
calculations have been carried out for u2 , σ2 and CR functions of Cu and Ni. The
ratio CR /u2 is 40% and CR / σ2 25% at high temperatures. They are found to be in
good agreement with experiment and with those calculated by the Debye model.
