Carol Garland working on the EM430 in room 042 Keck.

Transmission Electron Microscopy Facility

Facility Use

 The Transmission Electron Microscopy (TEM) Facility is located in the subbasement of the Keck Engineering Laboratory (Room 042). We have two transmission electron microscopes for materials research, both maintained under contract with Philips Service. The Philips EM430 (300 kV) is used for spectrometry and high resolution work (better than 2.3 A point-to-point in its sub-basement location). Our Philips EM420 (120 kV) is used for imaging and analytical work. Both microscopes have EDAX 9900 energy-dispersive x-ray analyzers, and the EM430 has a Gatan 666 parallel-detection EELS spectrometer. This EELS spectrometer has been modified by Dr. Channing Ahn to serve as an energy filter, and this configuration has been used to measure chemical maps of transition metals with 5 A spatial resolution. A Philips heating holder and a Gatan liquid nitrogen cooling holder are available. Specimen preparation facilities include electrochemical polishing and ion milling equipment, plus the standard tools of metallography.

The TEM facility has seen wide use from scientists across the Caltech campus in the Divisions of Engineering and Applied Science, Chemistry and Chemical Engineering, Biology, Geology and Planetary Sciences, and Physics Mathematics and Astronomy. We also encourage the use of the facility by scientists and engineers from the Los Angeles area. At present there are several active interactions with industrial and academic users from outside the Caltech campus. Carol Garland is the contact person for inquiries about the feasibility of microscopy analysis, and she can manage a number of preliminary or short-term projects. Training is available for users with long-term research projects. Scheduling is done by contacting the professional staff to make an appointment. Collaborative research is also welcome in cases where the interests of Caltech and the outside users coincide.

Rates charged to users are determined annually and vary with the instrument, amount of support needed, and billing arrangements required. For current rates and services available, contact:

Carol M. Garland, Member of the Professional Staff
          e-mail: cmg@cco.caltech.edu
             Fax: 626-795-6132
           Phone: 626-395-2168

Recent publications of Carol Garland

Microscopes

 Philips EM430 analytical transmission electron microscope is used for research and the Caltech class MS125. This 300kV TEM is run with a single crystal lanthanum hexaboride filament. Accessories include a STEM unit, energy dispersive x-ray detector, parallel energy loss spectrometer, high resolution CCD camera, and hot stage.

Philips EM420 analytical transmission electron microscope is used for both teaching and research. This 120kV TEM is run with a tungsten filament. Accessories include a STEM unit, secondary electron detector, backscattered electron detector, and a light element energy dispersive x-ray detector.

Nikon reflected light microscope with polarizer, analyzer, and Nomarski illumination is used for metallurgical studies. It has a television system interfaced to a frame grabber and digital image analysis system.

Equipment for Sample Preparation

The preparation of a sample that is transparent to electrons is frequently the critical step in the TEM characterization of a material. The sample preparation laboratory in 042 Keck includes standard and specialized equipment needed to prepare samples for observation by optical or transmission electron microscopy.


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