TY  - JOUR
A1  - Markus, Kathrin
A1  - Moroz, Lyuba
A1  - Arnold, Gabriele
A1  - Henckel, Daniela
A1  - Hiesinger, Harald
A1  - Rohrbach, Arno
A1  - Klemme, Stephan
T1  - Reflectance spectra of synthetic Fe-free ortho- and clinoenstatites in the UV/VIS/IR and implications for remote sensing detection of Fe-free pyroxenes on planetary surfaces
JF  - Planetary and space science
N2  - Both enstatite spectra are very bright in the VIS and NIR and show almost neutral to slightly bluish spectral slopes with a steep absorption in the UV. Very low iron in the enstatites (below similar to 0.04 wt% FeO) already results in weak albeit noticeable absorptions in the VNIR between 0.4 and 0.9 mu m. Orthoenstatite and clinoenstatite are not distinguishable based only on their spectra in the VIS and NIR. At the Reststrahlen bands in the MIR a systematic difference in the number and exact position of local minima at similar to 10 mu m between clinoenstatite and orthoenstatite is evident. This can be used to discern between the polymorphs in this wavelength range. Additionally, we can distinguish between Fe-free low- and high-Ca pyroxenes in the MIR.
KW  - Reflectance spectroscopy
KW  - Remote sensing
KW  - Enstatite
KW  - Synthetic pyroxene
KW  - Analog material
Y1  - 2018
U6  - https://doi.org/10.1016/j.pss.2018.04.006
SN  - 0032-0633
VL  - 159
SP  - 43
EP  - 55
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Klemme, Stephan
A1  - Feldhaus, Michael
A1  - Potapkin, Vasily
A1  - Wilke, Max
A1  - Borchert, Manuela
A1  - Louvel, Marion
A1  - Loges, Anselm
A1  - Rohrbach, Arno
A1  - Weitkamp, Petra
A1  - Welter, Edmund
A1  - Kokh, Maria A.
A1  - Schmidt, Christian
A1  - Testemale, Denis
T1  - A hydrothermal apparatus for x-ray absorption spectroscopy of hydrothermal fluids at DESY
JF  - Review of scientific instruments : a monthly journal devoted to scientific instruments, apparatus, and techniques
N2  - We present a new autoclave that enables in situ characterization of hydrothermal fluids at high pressures and high temperatures at synchrotron x-ray radiation sources. The autoclave has been specifically designed to enable x-ray absorption spectroscopy in fluids with applications to mineral solubility and element speciation analysis in hydrothermal fluids in complex compositions. However, other applications, such as Raman spectroscopy, in high-pressure fluids are also possible with the autoclave. First experiments were run at pressures between 100 and 600 bars and at temperatures between 25 degrees C and 550 degrees C, and preliminary results on scheelite dissolution in fluids of different compositions show that the autoclave is well suited to study the behavior of ore-forming metals at P-T conditions relevant to the Earth's crust.
Y1  - 2021
U6  - https://doi.org/10.1063/5.0044767
SN  - 0034-6748
SN  - 1089-7623
VL  - 92
IS  - 6
PB  - AIP Publishing
CY  - Melville
ER  -