2025/11/12 by А. И. Кривчиков, Krivchikov, A. I., A. Jeżowski +25
Materials Science · #Thermal properties of materials #Carbon Nanotubes in Composites #Graphite, nuclear technology, radiation studies
paper · pdf · doi:10.48550/arxiv.2511.09338
The specific heat of expanded graphite (EG) and EG--multiwalled carbon nanotube (MWCNT) composites (1.0 and 3.0 wt.% MWCNTs) was measured between 2 and 300~K. The low-temperature heat capacity is dominated by out-of-plane flexural phonons with quadratic dispersion, characteristic of two-dimensional layered systems. Compared with crystalline graphite, EG exhibits enhanced heat capacity due to increased defect density and reduced interlayer coupling. Structural characterization (XRD, Raman, EDS) confirmed variations in stacking order and defect concentration. The data were fitted using a three-term model (C1T + C3T3 + C5T5), where the negative C5 term indicates quadratic phonon dispersion. The results demonstrate the influence of MWCNT integration and structural disorder on phonon dynamics and anisotropic heat capacity in EG-based composites.