Effect of thermal disorder on thermodynamic EXAFS parameters of lead metal analyzed using quantum-statistical perturbation theory

Chúng tôi vui mừng thông báo rằng TS. Lê Duy Mạnh và các đồng nghiệp  đã xuất bản công trình có tựa đề “Effect of thermal disorder on thermodynamic EXAFS parameters of lead metal analyzed using quantum-statistical perturbation theory” trên tạp chí Physics of the Solid State (PS Solid State).

Tóm tắt:

The thermodynamic parameters of lead metal (Pb) are systematically analyzed within the framework of anharmonic extended X-ray absorption fine structure (EXAFS) theory, considering the effect of thermal disorder. The theoretical model is developed based on quantum-statistical perturbation theory combined with the correlated Einstein model, which considers both correlational and anharmonic effects when describing atomic interactions. The studied thermodynamic quantities include the correlated Einstein temperature and frequency, local force constants, anharmonic effective potential, first four EXAFS cumulants, EXAFS amplitude reduction, and EXAFS phase shift. The effect of thermal disorder is derived from the thermal vibrations, quantized as phonons, with anharmonicity resulting from phonon-phonon interactions within the crystal lattice. The obtained temperature-dependent expressions satisfy all required physical properties in both high- and low-temperature limits. Numerical results for Pb in the solid state exhibit agreement with those obtained from the fitting method and experimental data at temperatures ranging from 0 to 600 K. These results validate the efficiency of the present theoretical model in evaluating thermodynamic EXAFS parameters of similar metal crystals under the effect of thermal disorder.