Anharmonic
effective potential, correlation effects, and EXAFS cumulants
calculated from a morse interaction potential for fcc metals
Anharmonic effective pair potentials and effective local force constants
have been studied for fee metals, assuming an interaction Morse
potential and taking into account the influence of nearest neighbours of
absorber and backscatterer atoms. Analytical expressions for the first
three extended X-ray absorption fine structure (EXAFS) cumulants, as
well as for the atomic mean square displacements, have been derived as a
function of the Morse parameters. Numerical results for copper and
nickel are compared with experimental data. A good agreement is found
for the second cumulant. Non-negligible discrepancies are instead found
for the first and third cumulants, which are tentatively attributed to
the central nature of the Morse potential, which neglects many-body
effects. URI: http://repository.vnu.edu.vn/handle/VNU_123/31148
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