Trace Element Distribution in Zoned Kyanite of Thassos Island (Greece) Using Combined Spectroscopic Analyses.

Comprehensive mineralogical and petrographic studies require analytical methods capable to report the distribution of major to trace elements within crystals in order to unravel their formation conditions and subsequent evolution. Additionally, the investigation of transition elements (e.g.

Interpretation of the pressure-induced Raman frequency shift of the ν stretching bands of CH and N within CH-CO, N-CO and CH-N binary mixtures.

The relationships between the frequency shift of the ν stretching bands of CH and N with pressure (or density) and composition have been previously provided in the literature as reliable parameters for accurate empirical barometers and densimeters for the direct determination of the pressure or density of gas mixtures. However, the latter results still remain a pure description of the experimental data without any interpretation of the physical mechanisms hidden behind the variation trend of the observed peak position. The present paper is devoted to interpreting the origin of the pressure-induced vibrational frequency shifts of the ν stretching bands of CH and N within CH-CO, N-CO and CH-N binary mixtures at the molecular level.

Quantitative Measurements of Composition, Pressure, and Density of Microvolumes of CO-N Gas Mixtures by Raman Spectroscopy.

Quantitative analysis of gases by Raman spectroscopy is based on relative Raman scattering cross sections (RRSCS) and the evolution of different spectral parameters (peak position, peak area, peak intensity, etc.). However, most of the calibration data were established at low pressure (low density) and without evaluating the effect of the composition.