Instrumentation and Facilities
A wide range of modern analytical equipment for mineralogical, thermodynamic, and crystallographic research is available in the Department of Geological Sciences. Our two new Bruker D8 Advance X-ray powder diffractometers provide great flexibility in analyzing powders under a variety of conditions, from 77°K (-196°C) to 450°C, under a variety of atmospheres. One of these instruments is equipped with a solid-state energy-discriminating detector and can produce high-resolution diffraction data for a variety of mineralogic studies, including qualitative and quantitative analyses, determination of unit-cell parameters, and Rietveld refinement of crystal structures. The other Bruker instrument is equipped with a new Vantec position-sensitive detector capable of very rapid data collection. In its most rapid data collection mode, the instrument can measure 12 degrees of diffraction data every 0.1 seconds, making time-resolved studies possible. This diffractometer is equipped with an Anton-Paar TTK heating/cooling stage that allows us to examine samples at samples from -196°C up to 450°C under controlled-atmosphere conditions. This instrument will also shortly have a facility to simulate both the temperature and water vapor pressure on the Martian surface.
A thermal analysis laboratory, adjacent to the diffraction lab, is equipped with a TA Instruments Simultaneous Thermogravimetric Analysis/Differential Scanning Calorimeter (TGA/DSC) for quantitative studies of the thermal behavior of minerals. Plans for Fall 2005 call for the addition of a dedicated adsorption instrument that will allow measurement of the thermodynamics of mineral-adsorbate interactions. We initially plan to use this instrument to measure the thermodynamics of water in hydrous minerals that are potentially on the Martian surface. Supporting these two labs is a complete mineral preparation and clay mineral separation laboratory equipped with a variety of sample grinding and disaggregation devices, a high-speed refrigerated centrifuge, low- and high-temperature ovens, and a variety of sample-mounting devices for X-ray diffraction.
The electron microbeam laboratory is adjacent to the diffraction laboratory, and it is equipped with a new FEI Quanta 400 FEG (field-emission gun) Scanning Electron Microscope (SEM) with high-vacuum, low-vacuum and ESEM modes. The SEM has a backscattered-electron detector, a Peltier cold stage, and an PGT thin-window energy-dispersive X-ray spectrometer capable of analyzing elements down to C. The SEM is also equipped with an HKL electron back-scattered diffraction detector for crystal structure identification and orientation mapping and a Gatan Chroma-CL-SP full-color cathodoluminescence detector. Along with the SEM is an automated Cameca SX50 electron microprobe, with supporting sample preparation and photomicrographic equipment. The electron microbeam laboratory is supervised by a full-time research scientist, Chusi Li.
Dr. Mastalerz's coal petrography lab features reflected light microscopes equipped with photometry systems and fluorescence attachments. A standard photographic camera and a digital camera with image analysis software are available.