Raman Spectroscopy Lab

Application of Raman spectroscopy in earth sciences:
 

• Identification of mineral phases (mineral inclusions, daughter minerals in fluid inclusions, composition of the gas phase in fluid and melt inclusions)
• Dissolved anion concentration in fluid (CO₃^2-, HCO₃^-, PO₄^3-, BO₄^3- , SO₄^2- , HS^-,  OH^- )
• Identification of crystalline dimorphs and polymorphs (e.g., calcite-aragonite; sillimanite- kyanite- andalusite)
• Water and boron content and speciation in silicate glasses

Applications in gas hydrate research:
 

• In situ identification of structure and composition of gas hydrates during formation and growth
• Determination of cage occupancy during hydrate formation
• Investigation on hydrate formation kinetics

The GFZ Micro-Raman Spectroscopy Laboratory use a Horiba Jobin Yvon Laser Raman Triple LABRAM spectrometer equipped with an Olympus optical microscope. Spectra are collected with a Peltier cooled CCD detector. Depending on the experiment two different laser light sources can be used for investigations on gas hydrates: a 633 nm line of a He/Ne laser and a Nd:YAG laser providing a 532 nm line. The confocal technique provides an efficient way to obtain interference-free Raman spectra of speciments embedded in transparent matrix (grain mounts, thin sections) and for  hydrate crystals.

For Raman studies at  ambient pressure and  temperatures between -196°C and 1500°C we use LINKAM stages: THM600  stage for the temperature range -196 to 600°C and TS 1500 stage for ambient to 1500°C .

For Raman studies at pressures up to 25 kbar at temperatures ranging from -190°C to 1000°C we use a hydrothermal diamond-anvil cell.