In addition to a large array of analytical instruments maintained by individual faculty, the Department supports a variety of material characterization instruments for graduate students and researchers on a recharge basis.

Microprobe and Scanning Electron Microscope
Contact: Sean Mulcahy 510-643-1005

Electron Microprobe (EPMA). The Cameca SX-51 electron microprobe is a customized analytical instrument with 5 wavelength dispersive spectrometers (WDS), a high resolution quantitative energy dispersive spectrometer (EDS) system, along with backscatter electron (BSE), secondary electron (SE), absorbed current (ABS) and cathodo-luminescence (CL) imaging in addition to both reflected and transmitted light viewing. X-ray mapping and analysis automation using both beam and stage scanning is available for ultra-low magnification imaging.

Scanning Electron Microscope (SEM)
A Leo 430 SEM is available for general research and can be used for both secondary electron (SE) and backscattered electron (BE) imaging. Qualitative chemicalanalyses can be performed with a energy-dispersive X-ray detector (EDS). With the addition of a Peltier cooled charge coupled device (CCD) fiber optic camera in 1998, the new SEM is also used for electron backscatter pattern (EBSP) and orientation imaging (OIM) as applied to analysis of preferred orientation.

X-Ray Diffraction (XRD)
Contact: Tim Teague 510-642-3514

XRD is used to identify and characterize crystal phases in powdered samples. Minerals and synthetic crystals produce characteristic x-ray patterns that can be compared with a database of known phases using analytical software.
The department has a PANalytical X’Pert Pro diffractometer equipped with Cu, Co and Mo x-ray tubes and the very fast X’Celerator detector. Scans that took hours with our old conventional system can now be made in a few minutes. The unit has a 15 position sample changer and a set of low background sample holders for samples as small as 1 milligram.

X-Ray Fluorescence (XRF)
Contact: Tim Teague 510-642-3514

XRF is used for chemical analysis of a variety of materials including rocks, soils, cement, ceramics and archeological objects. For major elements (Na-Fe) 0.5g of sample is mixed with flux and fused into a glass disc. For trace element analysis 3g of powdered sample is pressed into a pill. Non-destructive trace element analysis is possible for such applications as archeology and art history.
The department has a Philips PW2400 wavelength-dispersive x-ray fluorescence spectrometer with light element capability. The five crystals installed in the unit allow the analysis of elements O-U. The instrument also includes a fully automated 30 position sample changer for extended analysis acquisition time.
We have a long relationship with the Archeological XRF Lab. They have a new Thermo QuantX energy- dispersive XRF, which is an excellent choice for non-destructive analysis of large objects and fast qualitative analysis of almost any type of material.

Stable Isotope Ratio Mass Spectrometer
Contact: Lynn Ingram 510-643-1474

In the Laboratory for Environmental and Sedimentary Isotope Geochemistry (LESIG), we are documenting past changes environmental and climatic conditions, including changes in salinity, stream flow, temperature, ocean circulation, and coastal upwelling at various locations, using environmentally sensitive isotopes (oxygen, hydrogen, carbon, strontium, and sulfur) and elements (such as Sr/Ca and Mg/Ca), contained in fossils, sediments, and other natural climate archives. We apply similar methods to studying modern environments, using Sr and light stable isotopes (O, C, N, H and S) as tracers. These analyses are made with a GV IsoPrime gas source mass spectrometer, MultiPrep, and elemental analyzer. The laboratory also has a computer-controlled micromill for very high-resolution sampling across incrementally banded growth layers, as well as sediment sampling and sample preparation laboratories, and a cold room, petrographic and binocular microscopes. The laboratories are located on the first floor of McCone Hall (rooms 115, 119, and 155).

Texture Lab
Contact: Rudy Wenk 510-642-7431

This laboratory is dedicated to the study of preferred orientation (texture) and anisotropy of polycrystalline materials. Various aspects are measurements, data analysis and interpretation. Applications include rocks, metals, polycrystalline films, ceramics, superconductors, biological specimens (bones, shells). The facilites are available to outside users on a recharge basis. Equipment includes X-ray pole figure diffractometer, EBSD SEM and sample preparation such as ion-beam thinner. The Texture Laboratory maintains software for quantitative texture analysis (BEARTEX) and provides introductions for texture analysis based on the Rietveld method from neutron diffraction data as well as synchrotron diffraction images.

Sample Preparation
Contact: Tim Teague 510-642-3514

The Department maintains extensive facilities for sample preparation producing thin sections, polished sections, rock powders and mineral separates. We have nine different diamond saws for cutting samples from 2mm to 30cm. There are automatic and manual grinders and polishers using diamond, SiC, alumina and colloidal silica. A variety of epoxies and temporary adhesives are available for different applications. Rock crushing and separating equipment includes a jaw crusher, disc mill, sieves, a shatterbox for making powders and two magnetic separators.