Equipment: Facilities and Equipment for our Research

The JEOL Hyperprobe using a Schottky fieldemission gun includes five wavelength dispersive X-ray spectrometers (WDS) with a detection limit around 20 ppm (10-5). 

We developed a novel laser ablation system to be used as micro-analytical tool in the elemental and isotope analysis of solid materials. The system is based on a femtosecond all solid-state Ti-sapphire based Laser operating at a fundamental wavelength tunable between 775-785 nm coupled to frequency conversion setup to produce deep UV laser radiation at wavelength of 196 and 262 nm. The system is combined with ICP based analytical intrumentation (ICP-OES and MC-ICP-MS).

Contact: Dr. Ingo Horn

Our ThermoScientific Element XR double-focusing sector field-inductively coupled plasma-mass spectrometer (SF-ICP-MS) is equipped with a Faraday detector and a dynode combined with a secondary electron multiplier (SEM). Hence it allows detection of a wide range of signal intensities (the dynamic range of counts per seconds encompasses 10¹² cps). This enables the analyses of ultra-trace element levels simultaneously with major elements. Three different modes of mass resolution allow separation of molecular interferences from signal peaks of interest. Except for H, He, C, N, O, and the noble gases, the Element XR at the Institute of Mineralogy is capable of analyzing every element of the periodic table.

Contact: Dr. Maria Kirchenbaur

The ICP-OES in our institute is an optical emission spectrometer of the type Varian 715-ES from VARIAN with an radial inductively coupled plasma and a patented VistaChip CCD simultaneous detector combined with an echelle raster. We use the ICP-OES for measuring major and trace elements in solution (mainly in 3% HNO3) or couple it to a femtosecond laser. Figure 2 shows elements that can be detected with the OES. The detection limits are different for each element, they are in the range of around 0.05 to 500µg/L. For precise determination of low trace element concentrations, the ELEMENT XR is available at the institute.

A reliable CETAC ASX 510 autosampler is available for high sample numbers. The ICP-OES is working with a 2 ml conical quartz glass nebulizer, a cyclone spray chamber, and torches made of quartz glass.

Contact: Alexandra Tangen

We have clean-air workstations that were installed by MK test facilities in 2002 and modernized by Arias GmbH in 2016. Each workplace is equipped with three pipettes (BioHit; 20 -200 µL, 100 - 1000 µL, 500 - 5000 µL). In addition, we offer workstations with two PicoTrace heating plates each for sample digestions. A third workstation is equipped with a PicoTrace heating plate for use with the PicoTrace DAS high-pressure high-temperature digestion system for temperatures up to 230 °C. The system can also be operated with perchloric acid, which is neutralized in an acid neutralization unit. All eight heating plates can be programmed via Arias control modules (including heating and cooling ramps as well as defined operating times).

At the institute three FTIR-spectrometers are available:

• Bruker Vertex 80v: spectral range 50-30000 cm-1

• Bruker IFS66v: spectral range 50-10000 cm-1, it has additionally a Raman-module FRA 106 with NdYag-laser (1000 nm) fitted. In addition, it is possible to measure temperature-dependent up to 600°C with a special sampleholder/oven-combination

• Bruker IFS88: spectral range 50-30000 cm-1, it is equipped with an IR microscope II. In addition it can be used with an heating/cooling stage in the temperature-range from -196 to 600°C or an high-temperature-heating-stage up to 1200°C

Contact: Prof. Dr. Claus Rüscher | Prof. Dr. Harald Behrens

The procedure has proven itself for the determination of the water content of solids such as minerals, glass and rocks:

• Programmer-controlled heating of samples in a platinum sample holder using a hf generator
• measurement of released water

Contact: Prof. Dr. Harald Behrens

Analyses of carbon and sulfur concentrations in metals, plants, and rocks are performed at the institute by using an ELTRA CS800 instrument. The sample material is weighed into a ceramic crucible. Iron and tungsten chips are then added to support later melting and oxidation of the sample. The crucible is transferred into  a sealed furnace which consists of an induction coil with the crucible resting in the centre of the coil. Induction of a strong magnetic field melts the iron and tungsten additives and ultimately also the sample material, and addition of oxygen oxidizes the released carbon and sulfur as CO₂ and SO₃, respectively. These gases are transferred to and detected by an infrared detection unit. The measured intensities are then converted into concentrations of C and S or CO₂ and SO₃.

Contact: Dr. Stefan Schuth

A small AC-voltage is applied on solid materials using a Novocontrol Alpha-Analyzer in the frequency range of 1 MHz down to 10^-3 Hz to determine the dielectric properties of the material by measuring the resulting electrical current. A Novocontrol ZG4 connection unit allows the 4-point-probe of dielectric sample characteristics. A high temperature sample holder in combination with a Nabertherm tube furnace, offers the possibility of temperature depending measurements from 20 °C to 1000 °C.

Contact: Prof. Dr. Harald Behrens

Determination of water contents of solids, determination of phase transitions, glass transition temperatures, decomposition temperatures and energy balances of chemical reactions.

Method:

• Computer-controlled heating of samples in corundum crucibles up to 1600°C
• analysis of mass variations using a microbalance with a precision of ±0,04 µg
• simultaneously temperature difference measurements to a reference using Pt-Rh-thermocouples for determination of characteristic energy conversions
• experiments can be performed in different gas-atmospheres or under vacuum

Contact: Prof. Dr. Claus Rüscher

The method yield supplementary information to Hg-porosimetry and tomography. Pathway for fluids in rocks and other ceramic materials can be determined. Pores and holes in porous materials can be characterized by intrusion of alloys such as "Wood's Metal" (50 Bi, 25 Pb, 12.5 Sn and 12.5 Cd in wt%; melting point of 78°C) or „Rose`s metal“ (50 Bi, 25 Pb, 25 Sn in wt%; melting point of 94°C). At a pressure of 550 bar connective pores with equivalent diameters as small as 20 nm are intruded with the molten alloy. Sample size of 5 mm; temperatures typically up to 120°C. After cooling polished sections are prepared and analyzed using an electron microscope.

Scanning electron microscopy plus qualitative and quantitative element-analysis for scientific investigation of solid-state materials in geosciences, civil engineering and cultural heritage preservation.

Contact: Prof. Dr. Josef-Christian Buhl

The Bruker Senterra Raman spectrometer is predominantly designed as an high-performance analytical instrument. It is equipped with an Olympus BX series with the FlexFocus™ system for confocal debth profiling and a set of objectives with long and short working distances. The CCD is an ANDOR DU420-OE with a thermoelectric cooling system with the  highest sensitivity between 400 – 900 nm.

Contact: Dipl. Geow. Marcel Dietrich

X-ray powder diffraction is used for qualitative and quantitative phase analysis of powdery samples for scientific material-analysis. For this purpose two modern diffractometer Bruker D4 Endeavor and Bruker D8 Advance are available. The D4 Endeavor is characterised by its ease of use and its high sample effort, while the D8 Advance can be used for special tasks, like small angle diffraction and temperature-depending diffraction.

Contact: Prof. Dr. Josef-Christian Buhl

A Nabertherm muffle furnace for temperatures up to 1400°C as well as three special furnaces for six steel autoclaves are available for the preparation of polycrystalline samples and single-crystals under dry and hydrothermal conditions. Two drying cabinets type Heraeus Kelvitron and a completely equipped wet-chemical laboratory for pre- and post-treatment of samples, complete the instrumentation.

Contact: Prof. Dr. Josef-Christian Buhl

Both vessels (WHITE and GREEN) are equipped with a Shaw-membrane to monitor the internal H₂ pressure; a rapid quench device allows cooling rates of  ~150°C/s. An Ar-H₂ mixture is used as pressure medium to adjust redox conditions inside the vessel. One vessel (WHITE) is equipped with a high-pressure low-flow metering valve to conduct decompression experiments with continuous decompression rates (~0.0002 to >10 MPa/s). The maximum heating rate is 80°C/min. The vessels are PC-operated (using itools) allowing e.g. to regulate the temperature path and logging of Ptotal, T, P(H₂).
The vessels are used to perform high pressure-temperature experiments (850 to 1250°C; up to 500 MPa) at various redox conditions (log fO₂ = FMQ+0 to FMQ+3) e.g. to investigate magmatic processes in earth’s crust or upper mantle and to synthesize high pressure materials. Decompression experiments can be conducted at geologically relevant P-T conditions to study degassing of volcanic systems.

Contact: Prof. Dr. Harald Behrens

The autoclaves of Tuttle-type (Cold Seal Pressure Vessel) are externally heated by a tube furnace and are pressurized with argon. Maximum temperatures are at 850°C at the maximum pressure of 500 MPa which can be applied in this system. Oxygen fugacity in the interior of water-filled capsules is about two orders of magnitude above the Ni/NiO buffer. Two vertically oriented autoclaves are equipped with a magnetic system allowing rapid heat and rapid quench of samples. With a three-zone furnace temperature gradients can be imposed to the autoclave.
The Ar-CSPV’s can be used for experiments at high pressure and temperature under oxidizing conditions, e.g., to simulate hydrothermal and magmatic processes in the Earth’s crust and in the upper mantle. Hydrothermal synthesis of minerals may be possible as well.

Contact: Prof. Dr. Harald Behrens