MISSION STATEMENT

The Electron Microbeam/X-ray Diffraction Facility is an integration of three laboratories comprising the following instruments: Cameca electron microprobe, Philips XL-30 scanning electron microscope/Princeton Gamma-Tech energy-disperision X-ray spectrometer, a Bruker X-ray powder diffractometer, and a Philips X-ray generator for powder and single-crystal cameras. Two preparation laboratories with a carbon evaporator unit, micronising mill, and other miscellaneous equipment, support these operations.

The microprobe, scanning electron microscope and preparation laboratory are housed in a specially-built low-vibration ground-floor laboratory complex with air conditioning and clean-air system; the X-ray powder diffractometer and preparation laboratory are housed elsewhere. Originally independent, these three laboratories have been merged into a modern analytical facility for the comprehensive characterization of minerals and materials. The Facility is managed by a university-paid Research Scientist/Honorary Professor (Mati Raudsepp); support personnell, comprising a full-time Research Scientists (Elisabetta Pani, Jenny Lai), and a part-time Research Assistant (S. Wilson), are supported from laboratory revenues.

Clients of the facility include researchers from within the department, numerous other departments at The University of British Columbia, University of Victoria, Simon Fraser University, Western Washington University, Federal and Provincial governments, and a large and diverse private sector - both local and international. In these laboratories, all work is done by the researchers. Graduate and undergraduate students, postdoctoral fellows and faculty are trained not only to operate the instrument but also in all aspects of this method of analysis: analytical strategy, data acquisition, data reduction and interpretation of the results. In addition, the electron microprobe, the scanning electron microscope and powder diffractometer are routinely included as a significant part of a graduate course in the characterization of minerals and materials taught by Raudsepp.

Both as a service to the public and to supplement income, the Facility provides analytical services to the private sector. Although quantitative phase analysis using the Rietveld method for exploration/mining, mineral processing and problems of environmental remediation is the major focus, a diverse range of services is also provided for clients from other engineering and technical fields, and from various industries in the high-technology sector.

DESCRIPTION OF EQUIPMENT

Electron microprobe

The laboratory is centered on a fully-automated Cameca SX-50 Scanning Electron Microprobe with 4 vertical wavelength-dispersion X-ray spectrometers and a fully-integrated SAMx energy-dispersion X-ray spectrometer. One of the spectrometers has two layered dispersion elements (W/Si, Ni/C), which allow the quantitative analysis of the light elements (F, O, N, C, B). There are standards for virtually all of the elements and common alloys. The instrument can produce X-ray element maps from EDS or WDS spectrometers, backscattered electron images, and secondary electron images.

Scanning electron microscope

A Philips XL30 electron microscope with Princeton Gamma-Tech energy-dispersion X-ray spectrometer and image analysis systems shares the clean lab with the microprobe, and allows quick examination and digital imaging of minerals and materials at both low and high magnifications. In addition to qualitative and semi-quantitative energy-dispersion chemical analysis of minerals, the state-of-the-art image analysis system is capable of automated feature analysis (e.g. size and shape of particles, chemical classification, relative area analysis), image processing of various signals (secondary electrons, backscattered electrons, characteristic X-rays, cathodoluminescence), and various metallurgical applications.

X-ray powder diffractometer

A Siemens (Bruker AXS) D5000 X-ray powder diffractometer allows quick collection of diffraction data for the qualitative identification of single mineral powders or mixtures of minerals from whole-rock powders. Diffraction data are processed by automated 'search-match' software which makes use of the complete International Centre for Diffraction Data PDF-4 database. The diffraction data may be output as colour-coded diffraction profiles, reflection lists, or as raw data files in ASCII format for additional user manipulation. Quantitative phase analysis of mixtures can be done using the standardless Rietveld method. Funding to upgrade the instrument with a modern high-speed detector (Bruker AXS VANTEC-1) has recently been awarded by NSERC.