[01] Nguyen Van Hung, Department of Physics, College of Science, VNU-Hanoi, Nguyen Trai, Thanh Xuan, Hanoi, Vietnam. [02] Dinh Quoc Vuong, Quang Ninh Education & Training Department, Nguyen Van Cu, Ha Long, Quang Ninh, Vietnam.

Thermodynamic properties and Debye-Waller factors of metallic Nickel described in terms of cumulant expansion up to the fourth order in X-ray absorption fine structure (XAFS) of metallic Nickel have been studied based on anharmonic correlated Debye model. Analytical expressions for dispersion relation, correlated Debye frequency and temperature, and four first XAFS cumulants have been derived which involve more information of phonons taken from integration over the phonon wave numbers varied in the first Brillouin zone. Derived anharmonic effective potential includes contributions of all nearest neighbors of absorber and backscattering atoms to take into account three-dimensional interaction and Morse potential parameters for describing single pair atomic interaction. Numerical results are found to be in good and reasonable agreement with experiment and with those of the other theories.

Thermodynamic Properties, XAFS Debye-Waller Factor, Cumulant Expansion

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