Characterization of Highly‐Oriented Carbon and Graphite Fibers by High‐Temperature Raman Spectroscopy

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

In this study, carbon and graphite fibers (GFs) using confocal Raman microscopy at 405 and 532 nm wavelengths are analyzed and explored the influence of incident laser power and sample temperature on the Raman spectra. At room temperature, the G- and D-band shifts of turbostratic fibers show a slight reduction with increased laser power, indicating potential surface heating under an inert atmosphere. In contrast, the graphitic fibers display consistent G- and G′-band positions across varying the laser power, with a noticeable decrease in D-band values at higher wavelengths. The ID/IG′ ratio for GFs is calculated with different excitation powers and wavelengths and indicates a constant value of 1.91 ± 0.12, suggesting that the fibers have fewer on-site (sp3 hybridization) defects compared to defect-free graphite, which has a higher ID/IG′ ratio of ≈3.5. The high-temperature Raman spectroscopy demonstrates linear correlations between Raman shifts and temperature for both types. For GFs, the G-band thermal coefficient (χG) is −0.0239 ± 2 × 10−3 cm−1 K−1, and that of D-band (χD) is −0.0177 ± 1×10−3 cm−1 K−1. For turbostratic fibers, the G-band thermal coefficient (χG) is −0.0358 ± 0.004 cm−1 K−1, significantly higher than that of GFs, likely due to the higher lattice disorder.

Details

Original languageEnglish
Article number2500107
JournalPhysica status solidi / Rapid research letters
Volume19
Issue number9
Early online date20 May 2025
Publication statusPublished - Sept 2025
Peer-reviewedYes

External IDs

ORCID /0000-0003-0675-6688/work/184887470
Scopus 105005531881

Keywords

ASJC Scopus subject areas

Keywords

  • carbon fibers, Raman-shift kinetics, in-situ high temperature Raman spectroscopy, G-band, Raman intensity ratios, D-band