‘Smart’ Raman/Rayleigh imaging of nanosized SiC materials using the spatial correlation model

Non-destructive Raman and Rayleigh microspectrometries were used to map nanostructural and topological variations across the diameter of the SCS-6™ Textron SiC fibre. It is shown for the first time that Rayleigh imaging offers a competitive alternative to AFM measurements for materials containing carbon as a second phase. The Spatial Correlation Model has been used to decompose the SiC Raman spectra into amorphous and crystalline components. ‘Smart’ Raman images, which contain the calculated structural parameters revealed the nanostructure distribution. A good agreement has been obtained at the nanoscale between these smart images and transmission electron microscopy (TEM) data. A major asset of Raman ‘smart’ images is to give a non destructive and global view on the crystal quality, grain size and residual stress. The potential and the limitations of the procedure are discussed.