Programme

P.6 -- Posters, VCTP-51

Date: Tuesday, 4 August 2026

Time: 09:30 - 10:30

Thermodynamic properties and melting temperature of FCC Cu–Ni alloys under high pressure

Nguyen Thi Hong (1), Nguyen Hoai Thanh (2), Tran Le Ngoc Tho (1)

(1) Hong Duc University (2) Hoang Giang Secondary school

In this study, the Debye model was developed to investigate the effect of high pressure on several characteristic thermodynamic properties and melting temperature of the face-centered cubic (FCC) Cu–Ni alloy, including the Debye frequency, Debye temperature, and Debye–Waller factor (DWF) and melting temperature. Based on the theory of lattice vibrations, expressions for the interatomic interaction potential in the FCC Cu–Ni alloy were constructed, forming the basis for describing the vibrational characteristics of the material system. From the established model, analytical expressions describing the volume (or pressure) dependence of the Debye frequency, Debye temperature, DWF and melting temperature were derived for Cu–Ni alloy across the entire pressure range under investigation. These analytical results were used to numerically calculate and analyze the variation of thermodynamic quantities with pressure. The results show that increasing pressure significantly affects the lattice vibrational characteristics of the alloy. Specifically, the Debye frequency and Debye temperature increase with increasing pressure due to the increased stiffness of the crystal lattice, while the DWF decreases, reflecting the reduction in the amplitude of atomic thermal vibrations under compression. The theoretical results were compared with available experimental and previously reported data, showing good agreement and confirming the reliability of the proposed model. This work provides a scientific basis for predicting lattice vibration properties, analyzing Extended X-ray Absorption Fine Structure (EXAFS ) spectra, and designing Cu–Ni alloy for high-pressure applications.

Presenter: Nguyen Thi Hong