No two samples will produce the same
Raman spectrum, making each measurement unique, similar to a fingerprint.
energy, and the abscissa of a
Raman spectrum displays shifts rather than
The
Raman spectrum is a molecular fingerprint of the material, and can be used to identify materials, typically by computing the correlation to a spectral library from the sample to a model of known materials.
The typical
Raman spectrum for high crystalline anatase structure should present one A1g band localized close to 520 [cm.sup.-1], two B1g bands localized close to 400 [cm.sup.-1] and also at 520 [cm.sup.-1] in overlapping with A1g band and finally, three Eg bands localized close to 150 [cm.sup.-1], 200 [cm.sup.-1] and 640 [cm.sup.-1], once the B2u vibrational mode is silent.
Deprotonation, degradation, and possible carbonization may occur during
Raman spectrum recording [21, 22].
Measurement of
Raman Spectrum. All Raman spectra in this paper were measured with dispersive Raman microscope of Horiba HP Evolution.
Each
Raman spectrum was measured with accumulation of 10 s, and averaged by 3 times.
The PCs were estimated by least-square fitting the first LVs and the sample spectrum, where the fitting coefficients were referred to these "new PCs" of each LV present in each
Raman spectrum of the commercial medicines.
Assume that y is a vector of the
Raman spectrum and z is the fitting vector; both of them are with the length of N elements.
Figure 4 shows the
Raman spectrum of R6G dripped on the surface of a silicon wafer and GO.