Author(s):
1. Dušan Ilić, Serbia
2. Siniša Vučenović, Republic of Srpska, Bosnia and Herzegovina
3. Stevo Jaćimovski, 4. Jovan Šetrajčić, Akademija nauka i umjetnosti Republike Srpske, Serbia

Abstract:
Phonon spectra and states in spatially very confined structures in one dimension – crystalline ultrathin – nanofilms were studied as a continuation of research on quasi two-dimensional systems. A comparison was made with the corresponding quantities in unconfined (bulk) crystal structures. By solving the Hamilton equation of motion, a system of homogeneous differential equations was formulated for determining the amplitudes of small mechanical disturbances (phonons) that propagated through the observed system. From the conditions of non-triviality of the solution of this system of equations, the phonon dispersion law was obtained with the main characteristic – the appearance of energy gaps. In the model structure, acoustic phonon branches of the optical type arise as an exclusive consequence of the finite boundaries of the system. The gap sizes determine the different thermodynamic behavior of the film structures.

Key words:
Ultrathin crystalline films,energy spectra,optical type of phonons.

Thematic field:
SYMPOSIUM A - Science of matter, condensed matter and physics of solid states

Date of abstract submission:
02.03.2026.

Conference:
Contemporary Materials 2026 - Savremeni Materijali

Applied paper from author