Nguyen Thi Hong, Nguyen Ba Duc, Ho Khac Hieu

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This work develops the anharmonic correlated Debye model to study the temperature-dependent extended X-ray absorption fine structure (EXAFS) Debye-Waller factors (DWFs) of B2-FeAl alloys. We derived the analytical expressions of the EXAFS DWF and Debye frequency as functions of temperature. Numerical calculations were performed for Fe1-yAly alloys with various Al concentration (y = 0.35, 0.40, 0.45 and 0.50) in which Fe-Al alloys still maintained B2 structure. The good agreement between our theoretical results with previous data verifies our developed theory. Our calculations show that DWFs of Fe1-yAly alloys increase robustly when temperature and/or Al concentration in Fe1-yAly alloys increase. The increasing of DWF will cause the reduction of the amplitude of EXAFS.

Keywords: EXAFS, Debye-Waller factors, Debye model, Anharmonicity, Fe-Al alloys.


[1] Y. Iwasawa, K. Asakura, M. Tada, XAFS Techniques for Catalysts, Nanomaterials, and Surfaces, Springer International Publishing, Switzerland, 2017.
[2] G. Bunker, Application of the Ratio Method of EXAFS Analysis to Disordered Systems, Nucl. Instruments Methods Phys. Res., Vol. 207, No. 3, 1983, pp. 437-444,
[3] P. Fornasini, F. Monti, A. Sanson, On the Cumulant Analysis of EXAFS in Crystalline Solids, J. Synchrotron Radiat., Vol. 8, No. 6, 2001, pp. 1214-1220,
[4] J. J. Rehr, Theoretical Approaches to X-Ray Absorption Fine Structure, Rev. Mod. Phys., Vol. 72, No. 3, 2000, pp. 621-654,
[5] N. V. Hung, N. B. Trung, B. Kirchner, Anharmonic Correlated Debye Model Debye-Waller Factors, Phys. B Condens. Matter, Vol. 405, No. 11, 2010, pp. 2519-2525,
[6] N. T. Hong, H. K. Hieu, N. B. Duc, D. D. Phuong, N. V. Tuyen, D. Q Khoa, Anharmonic Correlated Debye Model for Thermal Disorder in Iron-Rich B2-FeAl Intermetallic Alloy, Vacuum, Vol. 163, 2019, pp. 210-215,
[7] C. H. Zhang, S. Huang, J. Shen, N. X. Chen, Structural and Mechanical Properties of Fe–Al Compounds: An Atomistic Study by EAM Simulation, Intermetallics, Vol. 52, 2014, pp. 86-91,
[8] D. Brewe, D. M. Pease, J. I. Budnick, C. C. Law, Temperature-Dependent Vibrational Properties of NiAl, CoAl, and FeAl β-Phase Alloys, Phys. Rev. B, Vol. 56, No. 18, 1997, pp. 11449-11455,