The effect of electronic entropy on temperature peculiarities of the frequency characteristics of two interacting anharmonic vibrational modes in β-Zr

الأصل · EN

A 2D temperature-dependent effective potential is calculated for the interacting longitudinal and transverse L-phonons of β zirconium in the frozen-phonon model. The effective potentials obtained for different temperatures are used for the numerical solution of a set of stochastic differential equations with a thermostat of the white-noise type. Analysis of the spectral density of transverse vibrations allows one to determine the temperature at which β-Zr becomes unstable with respect to the longitudinal L-vibrations. The obtained temperature value practically coincides with the experimental temperature of the β→ α structural transition in zirconium. The role of electronic entropy in the β-Zr stability is discussed.