Quantitative Correlation Between Raman D′ Band Characteristics and Texture Fragmentation in Thermally Oxidized Graphite Using a Boundary Intersection Descriptor

Abstract

Establishing a direct and quantitative link between microstructural features and spectroscopic signatures remains a key challenge in the characterization of graphitic materials. In this work, thermally oxidized high-purity graphite is used as a model system to investigate the relationship between Raman spectral features and microstructural fragmentation revealed by field-emission scanning electron microscopy (FESEM). Controlled oxidative thermal treatment in air was applied to induce structural disorder while preserving the overall graphitic phase, as confirmed by X-ray diffraction (XRD).

A line-intercept–based boundary intersection descriptor (BID) was introduced to quantify microstructural fragmentation from FESEM images in a consistent and reproducible manner. Raman spectroscopy revealed a progressive evolution of the defect-related D' band with increasing treatment severity. Among the investigated Raman metrics, the full width at half maximum (FWHM) of the D' band exhibited a strong and systematic correlation with BID, whereas intensity- and area-based ratios showed a weaker and less consistent dependence on microstructural fragmentation.

The combined analysis demonstrates that D'-band linewidth broadening provides a sensitive and physically meaningful spectroscopic probe of in-plane disorder associated with flake fragmentation and boundary density. This study highlights the advantage of linewidth-based Raman descriptors over conventional intensity metrics and establishes a framework for correlating Raman spectroscopy with electron microscopy in graphitic and other layered materials.