IPG Photonics

About: IPG Photonics is a based out in . It is known for research contribution in the topics: Laser & Fiber laser. The organization has 903 authors who have published 1241 publications receiving 63339 citations.

Theoretical infrared absorption coefficient of OH groups in minerals

Abstract: The integrated molar absorption coefficient of isolated and localized OH groups in selected minerals is theoretically investigated within the density functional theory framework. The overall decrease in absorption coefficient of stretching modes observed with increasing frequency is consistent with the experimental observations. It is related to a decrease in the magnitude of the hydrogen Born effective charge tensor projected along the OH bond as a function of increasing H-bonding. The scatter of theoretical data shows that the use of a general calibration of infrared absorbances in minerals cannot lead to accurate water contents. In contrast, the combination of theoretical modeling and experimental measurements should improve the determination of the hydrogen distribution among structurally distinct OH defects in nominally anhydrous minerals.

Dissolution of strontianite at high P-T conditions: An in-situ synchrotron X-ray fluorescence study

Abstract: In-situ measurements of the amount of dissolution of carbonate minerals at high pressures (up to 3.6 GPa) and temperatures (up to 523 K) are reported. Using an externally heated diamond anvil cell (DAC) and synchrotron X-ray fluorescence (SXRF), the extent of dissolution of strontianite (SrCO3) has been followed as a function of time by monitoring the fluorescence of Sr cations in the fluid surrounding the crystal. This work demonstrates that Sr2+ concentrations as low as 1000 ppm can be detected and measured in-situ in a DAC, using a forward transmission geometry. The preliminary data presented here indicate that this technique has high potential for determining solution composition in high-pressure and high-temperature geochemical studies.