Programme

P.37 -- Poster, VCTP-48

Date: Thursday, 3 August 2023

Time: 08:30 - 10:00

Analysis of thermodynamic parameters of metallic platinum in anharmonic EXAFS theory under the influence of thermal disorders

Tong Sy Tien (1,*), Nguyen Thi Minh Thuy (1), Vu Thi Kim Lien (1), Ho Van Yen (2), Nguyen Cong Toan (3), Nguyen Bao Trung (3)

(1) Faculty of Fundamental Sciences, University of Fire Prevention & Fighting, 243 Khuat Duy Tien, Hanoi 120602, Vietnam; (2) Faculty of Fundamental Sciences, Artillery Officer School, Thanh My, Son Tay, Hanoi 154210, Vietnam; (3) Department of Physics, Hanoi University of Science, 334 Nguyen Trai, Hanoi 120034, Vietnam

The thermodynamic parameters of metallic platinum (Pt) have been calculated and analyzed under the influence of thermal disorders in the anharmonic Expanded X-ray absorption fine structure (EXAFS) theory. The calculation model is developed based on the correlated Einstein model and quantum-statistical perturbation theory using an effective potential method. Thermodynamic parameters are considered, including the local force constants, Einstein frequency, Einstein temperature, interatomic distances, mean square relative displacement, and thermal expansion coefficient. The influence of thermal disorders on these parameters is derived from the thermal vibrations of all atoms, with each thermal vibration that is quantized and treated as a phonon, and the anharmonicity is the result of phonon-phonon interactions. The obtained expressions can satisfy all their temperature-dependent fundamental properties. The numerical results of Pt agree well with those obtained from the other theoretical models and experimental data at various temperatures in the range from 0 K to 1000 K. The obtained results indicate that the present model can efficiently investigate the thermodynamic parameters of Pt.

Presenter: Tống Sỹ Tiến