INDEX

Overview
Center Facilities
Transmission Electron Microscopes
Scanning Electron Microscopes
Ga+ Focused Ion Beam System
Specimen Preparation
Image Acquisition and Analysis
The Board of Directors

Overview

The Electron Microscope and Image Processing Facility located in the Department of Materials Science and Engineering (MSE) in the School of Engineering and Applied Science (SEAS) at the University of Virginia (UVa) is a state-of-the-art facility dedicated to microscopy and microanalysis of materials from atomic to microscopic levels. The center has three transmission electron microscopes (TEMs), two scanning electron microscopes (SEMs), a focused Ga+ ion beam (FIB) microscope, extensive hardware/software for image simulation, processing and analysis, and a variety of specimen preparation equipment. More detailed information about the microscopes and capabilities is provided below. Some of the capabilities include: The Electron Microscope and Image Processing Facility is available for use by all qualified faculty, students and researchers at UVa, as well as by researchers from other universities and industries. Scheduling is handled on a first-come first-serve basis by sign-up sheets associated with each piece of equipment. A technician, students and faculty are available to assist researchers using the instruments, and two 3-credit courses in electron microscopy are offered each year. At any given time, the facility is typically used by about half of the faculty and students in MSE, as well as by several researchers from other departments in the School of Engineering and Applied Science, Physics, Biology, and from nearby universities and industries.

Sue

Graduate student Sue Kazanjian utilizing the JEOL 4000EX microscope.


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Center Facilities

Transmission Electron Microscopes

The most recent microscope is a JEOL 2010F, 200 kV TEM equipped with a thermal field-emission source, an Oxford Pentafet ultra-thin window energy-dispersive X-ray spectrometer (EDXS) and a Gatan imaging filter (GIF). This microscope has a point resolution of 0.23 nm, an information limit of 0.14 nm and ± 30° double-tilt capability with the JEOL low-background analytical holder. It can form a 1 nm probe with 1 nA of current on the specimen and a 0.5 nm probe with about 0.3 nA of current. These probe/current relationships allow EDXS analysis of 0.5-1.0 nm areas of a thin foil with reasonable counting statistics. X-ray spectra are collected and analyzed using the NIST Desktop Spectrum Analyser (DTSA) software package. The GIF contains a slow-scan CCD camera (SSC), a TV-rate camera, a parallel electron energy-loss spectrometer (PEELS) and two Macintosh Quadra computers (840AV and 660) for data acquisition and analysis. Gatan's Digital Micrograph and EL/P software are used for digital imaging, energy-filtered imaging and PEELS analysis. Although film is used in the microscope, most data are acquired digitally on the Quadra 840 and stored on user disks through a Zip drive. This microscope also has Gatan low-background double-tilt hot-stage (25-1000°C) and cold-stage (liquid nitrogen) specimen holders.

Omega

Nanoprobe X-ray analysis from the JEOL 2010F microscope showing segregation of Ag to precipitate interfaces in an Al-Cu-Mg-Ag aircraft alloy.


A JEOL 4000EX 400 kV top-entry high-resolution TEM (HRTEM) with a LaB6 filament is also available. This microscope may be configured with one of two objective lens pole-pieces, either an ultrahigh-resolution pole-piece with 0.17 nm point resolution and ± 20° tilit, or a high-resolution double-tilt ( ±10°) hot-stage (25-800°C) with 0.18 nm point resolution. The higher accelerating voltage and better point-resolution of this microscope make it preferable to the 2010F for many HRTEM and in situ hot-stage experiments. The 4000EX has a TV-rate camera that is connected to a VCR and to a Quadra 950AV computer with Digital Micrograph software for in situ recording and image analysis, respectively.

TiAl

Experimental and simulated (inset) HRTEM images of the coherent interface between TiAl (gamma) and Ti3Al (alpha-2) phases in a TiAl-base alloy.


Conventional TEM studies are performed on a JEOL 2000FXII 200kV TEM equipped with a LaB6 filament, high-angle PGT EDXS detector, Gatan slow-scan and wide-angle TV-rate cameras and a variety of specimen holders, including heating, cooling and straining stages with tilting capability. This instrument has a high-tilt pole-piece with a point resolution of 0.3 nm and ± 60° double-tilt capability using the Gatan low-background double-tilt holder. The SSC on the 2000FXII is connected to a Quadra 840AV for image acquisition and analysis. X-ray spectra are analyzed using a Tracor-Northern 5500 Series II system.

316SS

TEM image of deformed 316 stainless steel showing dislocations and dipoles on (111) planes.


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Scanning Electron Microscopes

The facility recently acquired a completely digital JEOL JSM-6700F cold field-emission gun SEM. This microscope operates at accelerating voltages ranging from 0.5 to 30 kV in 0.1 kV steps and has a guaranteed resolution of 1.0 nm at 15 kV and 2.2 nm at 1.0 kV. It has secondary electron imaging (SEI) capability utilizing both through-the-lens and in-chamber secondary electron detectors and backscattered electron imaging (BEI) with both compositional and topographical imaging contrast. The microscope is equipped with a monochromator cathodoluminescence system for imaging and spectroscopy of light emitted from the specimen. It is also equipped with a PGT IMIX-SPIRIT energy-dispersive X-ray spectroscopy (EDXS) detector with an ultra-thin window for light element detection down to boron. This system permits image collection with a complete spectrum stored for each pixel in the image. The system utilizes a Windows 2000 operating system running on a 933 MHz Dell computer with a 40 GB hard drive for image storage and processing. The specimen stage is fully computer controlled, allowing for automation of X, Y, Z, tilt and eucentric rotation. A liquid-nitrogen cooling stage and a heating stage are available for in situ temperature experiments.

TiAlloy

SEM image of matrix and grain boundary precipitates in Ti-6-22-22 alloy. The precipitates are dark and the matrix is light.

A second SEM, a JEOL JSM-840A, is equipped with a LaB6 filament and a PGT EDXS system for high-resolution imaging (4 nm) and microanalysis of elements down to Be. This instrument has SEI and BEI, as well as HKL Technology electron backscattered pattern (EBSP) hardware and software for orientational imaging and mapping of specimens. It also has a NPGS electron-beam lithography system. The microscope has extensive automation, image storage and processing capabilities.

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Ga+ Focused Ion Beam System

An FEI200 Ga+ FIB microscope under the direction of Prof. R. Hull is also available in conjunction with the electron microscope facility, to perform microstructural engineering, characterization, imaging and modification of surfaces at the nanometer level. The FIB employs a highly collimated Ga+ beam with 10 nm probe resolution and a maximum current of 10 nA. This technique can be used for controlled deposition, sputtering or reactive gas etching to provide nanomachining and lithographic capabilities with 10 nm resolution. Simultaneous imaging is available through secondary electron or seconday ion imaging. A secondary ion mass spectrometer (SIMS) is also available to determine the specimen chemistry. The ability to simultaneously etch, image and analyze provides a route to nanoscale tomography or three-dimensional imaging of device and structure properties.

Dave

Graduate student Dave Mathes working on the FEI200 FIB microscope.


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Image Acquisition and Analysis

The slow-scan and TV-rate cameras on the three TEMs are connected to Macintosh computers with Gatan's Digital Micrograph software for image acquisition and analysis. SuperVHS VCRs are also available for real-time image recording. The Macintosh computers are networked to a Codonics color dye-sublimation printer and several different Apple Laserwriters. Software for calculating diffraction patterns (Desktop Microscopist, for example), simulating HRTEM images (MacTempas), image processing, etc., is available on the Macintosh computers. Digital imaging and image processing are accomplished using the Tracor-Northern and Kevex systems on the JXA-840A and JSM-840A SEMs. Dark-room facilites are available for processing negatives and printing images.

FIB

Secondary electron image (left), secondary ion image (center) and Al elemental map (right) of contact layers in an electronic device, taken on the FIB system.

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Specimen Preparation

A variety of specimen preparation equipment is available including: two Gatan Dual Ion Mills (model 600) equipped with cold-stages and laser cut-off controls for thinning non-metallic and brittle specimens, Struers Tenupol-3 and Fischione twin-jet electropolishers for thinning metallic samples, a Fischione dimpler for mechanical thinning of specimens, a wide variety of metallographic cutting and polishing equipment for sectioning samples, Technics Hummer and Anatech Hummer VI systems for metal sputtering and carbon evaporation, and equipment for preparing 3 mm discs such as an electro-spark cutting mill, an ultrasonic abrasive disc cutter and mechanical punches.

DuoMill

Gatan DuoMill (model 600) equipped with cold-stages and laser cut-off controls.

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The Board of Directors

Title Phone E-mail
Mr. Richard White Facility Manager 434-982-5657 rrw3q@virginia.edu
Prof. James M. Howe Facility Director 434-982-5646 jh9s@virginia.edu
Prof. James M. Fitz-Gerald Scanning Electron Microscopy 434-243-8830 jmf8h@virginia.edu
Prof. Robert Hull Focused Ion-Beam System Manager 434-982-5658 rh5c@virginia.edu

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