NEW TECHNIQUE ALLOWING FT-RAMAN MEASUREMENTS OF ROTATING SAMPLES

Sample rotation combined with Fourier transform (FT)-Raman spectroscop y usually results in spectra severely distorted by a double modulation of the scattered light emitted by the substance under study. In the c ase of accurately aligned solid samples, the disturbance modulation is mainly due to an optical inhomogeneity of the surface, e.g., a certai n surface roughness. The application of the step-scan technique permit s the laterally resolved investigation of rotating samples when the mo vement of the interferometer mirror of the FT-Raman spectrometer is sy nchronized to the rotation of the sample, Routine FT near-infrared (NI R) Raman spectroscopic measurements of thermally sensitive and inhomog eneous solid samples that require the application of a spinning-sample arrangement become possible, Moreover, information about the angular dependence of the physical and chemical surface composition of the sol id samples, i.e., a lateral resolution, can be obtained.