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Electron Optics - TEM

The World's Best Electron Microsocope

By June, 2008 two, new ultrahigh resolution microscopes were commissioned. Recent breakthroughs in the development of advanced electron microscopes were combined to produce an instrument with unprecedented spatial and energy resolution. With this instrument, Canadian and International microscopists will be able to redefine the science of eletron mocroscopy achieving remarkable insights into the behavior of materials on all length scales.

A new electron microscope for biomaterials ... the VG STEM lives again!

The system was donated by the Ontario Cancer Institute (OCI)-Princess Margaret Hospital (Toronto) to the Brockhouse Institute at McMaster University following several years of use by Professor Peter Ottensmeyer and his group at OCI. Professor Ottensmeyer lead the microscopy group at OCI and commissioned this state-of-the-art microscope in 1994 following a successful grant application to CIHR. Following the retirement of Prof. Ottensmeyer, the system was transferred to a good home to take on new challenges.

The microscope has been upgraded with brand-new electronics and a fast parallel EELS spectrometer (Gatan’s Enfina) following a successful NSERC application lead by Prof. Botton (Materials Science and Engineering), Prof. Joaquin Ortega (Biochemistry and Biomedical Sciences) and Prof. Alex Adronov (Chemistry). The system will be housed in the Canadian Centre for Electron Microscopy within the Brockhouse Institute for Materials Research and be available to all users from across Canada.

TEM/STEM

The electron optics facility currently operates 3 electron microscopes.

The JEOL 2010 field emission TEM/STEM is a versatile analytical instrument with a very high brightness electron source. The maximum magnification in transmission mode is 1.5 million and the information limit is 1.4 Å. It is capable of convergent beam and selected area diffraction analysis. In STEM mode its spot size has been optimized to 1 nm. This allows for high magnification imaging (X 8 million) and energy dispersive analysis of materials. The small spot size enables elemental analysis with special resolution limited by the scattering in the specimen (for nanoparticles it can be as small as the beam size but for thicker specimens it can be 5-10 nm depending on the nature of the sample).

The CRC-CFI-OIT funding allowed the purchase of a new generation of electron energy loss spectrometer-energy filter to be installed on the JEOL2010F. This filter, developed by Gatan, is the first of its kind. It offers new features not present in the current models commercially available. The features include a more sensitive detector, faster readout technology and improved transfer function for higher resolution imaging and quantitative microscopy. The system also includes additional aberration correctors allowing larger fields of view to be seen and a field cancellation system. This spectrometer is the first one to be installed by Gatan in any laboratory and therefore is unique in the world. This spectrometer-filter maps the chemical composition at nanometer spatial resolution and produces energy loss spectra. It is therefore an instrument with tremendous impact for a large number of national and international users of the TEM.

With this new system it is now possible to acquire images, X-ray spectra and energy loss spectra simultaneously in STEM mode. Other instrumentation purchased with CRC-CFI-OIT includes new cameras, new detectors, a digital multi-channel analyzer and computers for quantitative simulations of atomic resolution images and energy loss spectra.

Separate funding from NSERC allowed the purchase of a new high-angle annular dark-field detector that will be used to obtain Z-contrast images. This system will be integrated on the2010F with the energy loss filter and the other data acquisition systems.

The Philips CM12 TEM is a valuable analytical and investigative tool for both hard and soft materials. A wide variety of materials can been examined at medium to low magnification following difficult and sometimes unique preparation techniques. The TEM has in situ hot and cold stages to enable operation from - 170 to 850°C.

Ancillary equipment for sample preparation include: Ultrasonic Disc Cutter, Dimple Grinder, Ion Thinner with Dual Cold Stage, Precision Ion Polishing System, Spark Erosion Wire Saw, Jet Polisher and Evaporator and Sputter coating equipment. The facility recently acquired remote access to a Focused Ion Beam facility maintained at Fibics Corporation in Ottawa.