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Vol.4 , No. 1, Publication Date: Feb. 5, 2018, Page: 10-16
 of hcp crystals have been studied. The advances in these studies are shown by a derived method using that the calculations and measurements are necessary only for the second cumulants from which all the considered XAFS quantities have been provided. It has resulted based on the description of XAFS expressions derived using the anharmonic correlated Einstein model in terms of second cumulants. The many-body effects included in the present one-dimensional model are taken into account based on the first shell near neighbor contributions to the vibration between absorber and backscaterer atoms. Morse potential is assumed to describe the single-pair atomic interaction included in the anharmonic interatomic effective potential. Numerical and experimental results for Zn in hcp phase obtained by the present advanced method are found to be in good agreement with one another and with those measured at HASYLAB (DESY, Germany).&picture=http://www.aascit.org/aascit/decorators/img/journal/891.jpg)
| [1] | Tong Sy Tien, Department of Basic Sciences, University of Fire Fighting & Prevention, Hanoi, Vietnam. |
| [2] | Nguyen Ba Duc, Department of Physics, Tan Trao University, Tuyen Quang, Vietnam. |
| [3] | Ha Dang Khoa, School of Engineering Physics, Hanoi University of Science and Technology, Hanoi, Vietnam. |
| [4] | Nguyen Van Hung, Department of Physics, VNU Hanoi University of Science, Hanoi, Vietnam. |
Theoretical and experimental Debye-Waller factors presented in terms of cumulant expansion and thermal expansion coefficient in X-ray absorption fine structure (XAFS) of hcp crystals have been studied. The advances in these studies are shown by a derived method using that the calculations and measurements are necessary only for the second cumulants from which all the considered XAFS quantities have been provided. It has resulted based on the description of XAFS expressions derived using the anharmonic correlated Einstein model in terms of second cumulants. The many-body effects included in the present one-dimensional model are taken into account based on the first shell near neighbor contributions to the vibration between absorber and backscaterer atoms. Morse potential is assumed to describe the single-pair atomic interaction included in the anharmonic interatomic effective potential. Numerical and experimental results for Zn in hcp phase obtained by the present advanced method are found to be in good agreement with one another and with those measured at HASYLAB (DESY, Germany).
Keywords
XAFS Cumulant, Thermal Expansion Coefficient, Correlated Einstein Model, Hcp Crystals
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