Microscopy facility

The field ion microscope allows for the observation and manipulation of atoms at the apex of a sharp probe. Built in house, this ultrahigh vacuum microscope uses various imaging gases, including helium, neon and nitrogen. The probe can be heated to 2000 °C and cooled between room temperature and 12 K for imaging. Up to 50kV can be utilized for imaging and tip shaping. Single atom tips are routinely prepared, and their ion source emission characteristics are evaluated in this microscope. This instrument can also operate in field emission mode where the electron emission characteristics of nanotips can be evaluated.

This 300 kV instrument is aimed at the practical application and examination of exposure to gases and liquids on samples. This instrument is equipped with an electron energy loss spectrometer for energy filtering imaging and chemical analysis. Like the HF-3300, the H9500 instrument and accessories in the laboratory are fully computer controlled. Samples for this microscope can be prepared iteratively using holders that can be shared between our Hitachi NB-5000 dual beam (FIB / SEM) instrument, this instrument, and the Hitachi HF-3300. Environmental TEM at cryogenic temperatures is now being investigated in this microscope.

The Hitachi HF-3300 is a 300 kV TEM and scanning TEM (STEM) equipped with a cold field emission gun, 3 electron biprisms and an electron energy loss spectrometer. The microscope development for custom experiments is by virtue of easy access and control of all electro-optical elements and hardware that is amenable to customization. This microscope grants us the ability to obtain emission with an electron acceleration potential as low as 1 kV, although 100 kV and 300 kV are most frequently used.

Key features:

• 6 planes for sample or phase modulating devices
• 360-degree sample tilt holder for electron tomography
• Momentum-resolved electron energy loss spectrometry in the optical region
• Hole-free phase plate imaging have been utilized to analyze magnetic skyrmion samples
• Bessel beams have been constructed and characterized in this microscope

The Hitachi HT7700 120 kV TEM and scanning TEM instrument in our facility is equipped with LaB6 or W source and supplemented by an in-house developed automation software. We collect a wide variety of data sets and perform automated sample heating sequences with data collection at determined states of the experiment. At present, we are developing methods for routine quantitative mapping toolbox in this instrument. The toolbox will enable the recurrent collection of data that provides local mass thickness information rather than merely lateral dimensions of objects in the image.

This dual beam instrument (focused ion beam and scanning electron microscope) is used for sample fabrication and custom prototyping of nano devices, in particular magnetic nano-mechanical devices. The samples can then be transferred to the HF 3300 and the H9500 ETEM for imaging and analysis.

The Hitachi S-5500 is a 30 kV instrument with an in-lens sample position. As a result, resolution of this instrument is sufficient to observe lattice image in graphite. This instrument is more frequently utilized for chemical mapping using EDX. An in-house developed environmental cell for this microscope promotes the convenient examination of sample behaviour under exposure to gaseous substances.

This microscope is based on a field ion microscope; however, it is specifically designed to characterize hydrogen ion sources from nanotips and single atom tips. The microscope can magnetically separate and mass analyze the ions emitted from nanotips. This provides the means to observe multiple species, including catalytically prepared reaction products that take place at atomic sites on the nanotip.

The JEOL 2200 is a 200 kV TEM / scanning TEM with Schottky electron source and cryo-polepiece. This instrument is optimized for imaging soft material science samples under cryogenic conditions. The large-gap polepiece promotes cryo electron tomography. The in-column energy filter provides a convenient means for electron energy loss spectroscopy, energy filtering imaging and diffraction. The excellent stability of both the in-column spectrometer and high voltage enables extended experiments to take place. The JEOL 2200 FS is the world's first instrument allowing hole-free phase plate imaging (note: the NRC-JEOL patented imaging is sometimes incorrectly referred to as Volta phase plate imaging). This is the instrument where hole-free phase plate was discovered and has been continuously developed for over a decade. While the most evident applications of phase plate imaging concern biological samples, it is noteworthy that phase plate imaging has recently been employed for studying magnetic samples, ultra-thin materials science samples and block copolymers samples.

Built entirely in-house, this custom, ultrahigh vacuum scanning tunneling microscope has 3 scannable probes, each achieving atomic resolution. Probes have scan ranges from 2 μm × 2 μm × 2 μm to 5 μm × 5 μm × 1 μm depending on the probe position. Each scanner is mounted on independent 3D coarse positioning motors with 10 mm × 10 mm × 10 mm travel in any direction. The probes can overlap and observation of the probe placement is guided by a 30 nm resolution SEM. This microscope also has the ability to prepare and condition single-atom tips using an attached field ion microscope. The microscope has measured the electrical resistivity of a single atomic step and can make electrical contacts to lithographically prepared samples while achieving atomic resolution imaging.

In ultrahigh vacuum, the Omicron variable temperature (VT) STM utilises a scanned tip design with a single tube scanner which has a scan range (xyz) of 12 μm × 12 μm × 1.5 μm. The scanner is mounted on an independent, orthogonal and guided 3D coarse positioning device with 10 mm × 10 mm × 10 mm travel in xyz direction. The system employs the VT XA version that uses a firm cooling connection and an embedded heater element to cover a temperature range from 50 K to 650 K. The XA version provides maximum compatibility with various other surface science techniques and also includes 4 additional electrical contacts to the sample for special experiments and connecting to lithographically prepared test samples.

In ultrahigh vacuum, the Omicron variable temperature (VT) STM utilises a scanned tip design with a single tube scanner which has a scan range (xyz) of 12 μm × 12 μm × 1.5 μm. The scanner is mounted on an independent, orthogonal and guided 3D coarse positioning device with 10 mm × 10 mm × 10 mm travel in xyz direction. The system employs the VT XA version that uses a firm cooling connection and an embedded heater element to cover a temperature range from 50 K to 650 K. The XA version provides maximum compatibility with various other surface science techniques and also includes 4 additional electrical contacts to the sample for special experiments and connecting to lithographically prepared test samples.

The Dimension 3100 Scanning Probe Microscope (SPM) produces high-resolution, 3-dimensional images by scanning a sharp tip over the sample surface. The tip is part of a flexible cantilever mounted on one end of a cylindrical piezoelectric tube mounted near the top of the microscope. Voltages applied to the X and Y electrodes on the piezoelectric tube deflect the tube horizontally to produce a precise raster scan over the sample surface. A voltage applied to the Z electrode on the piezo tube controls the vertical height of the tip. A stepper motor coupled to a lead screw translates a slide with the sample attached. A separate motor drive controls the height of the microscope and tip relative to the sample surface. The dimension 3100 is more user-friendly than the multimode AFM as it has a motorized stage that allows the operator to mount much larger samples. Moreover, engaging is automatic once the positions of the tip and the sample are determined by focusing the optical microscope.

Key features:

• Sample size 150 mm diameter 12 mm thick
• Stage movement x-y 150 mm with 2 micron resolution
• Video optics with zoom 150-675 micron viewing area
• Piezo scan head range; 90 micron x-y and 6 micron in z
• 16 bits DAC giving sub nanometer resolution
• Max 512 x 512 samples/image
• Contact and tapping mode AFM
• Conductive AFM & STM

The MultiMode atomic force microscope (MM-AFM) is designed for imaging small (approximately 1.5 cm diameter) samples using a series of interchangeable scanners and is able to provide ultrahigh-resolution images from the atomic scale to 175μm in size. The MM-AFM is designed around a stationary probe, which means that samples are scanned back and forth beneath the probe. Typically, samples are fixed to round 1.5 cm metal disks (pucks), then magnetically attached to the top of the scanner tube. As the scanner moves back and forth, the sample moves with it, allowing the probe to extract information from the sample's surface.

Key features:

• Contact and tapping mode AFM
• Conductive AFM & STM (including low current STM)
• Fluid operation: contact and tapping mode AFM in fluids
• Lateral mode and force imaging
• Point & shoot mode force mapping
• Magnetic force imaging
• High-temperature AFM (up to 250 ^oC)

This dual-beam instrument (focused ion beam and scanning electron microscope) is used for sample fabrication and custom prototyping of nano devices, in particular magnetic nano mechanical devices. Adding to the unique features of this instrument is the possibility to prepare samples at cryogenic temperature. The samples can then be transferred to the JEOL 2200 FS for imaging and analysis.