Products: The UltraSTEM range

Atomic-resolution EELS chemical composition map taken on the Nion UltraSTEM 100 microscope. V = red, La = green, Ti = blue. Yellow arrows point to purple bands showing V/Ti intermixing. This 128x375 pixel spectrum-image was taken at 10ms/pix (~15 min total acquisition) with no drift compensation. (Courtesy L. Fitting-Kourkoutis & D. Muller)

ADF image of monolayer boron nitride containing atomic substitutions. Quantitative analysis of the image produced a detailed atomic model, which is shown superposed on the image. Boron atoms are shown red, carbons atoms yellow, nitrogen atoms green and oxygen atoms blue. Graphic courtesy Tim Pennycook, ORNL & Vanderbilt U.

Nion microscopes have been designed from the “ground up”. This has allowed them to avoid having any “historical design baggage” that is typically found in other electron microscopes. The result is an integrated performance second to none.

Nion microscopes have many features not found in other instruments, with benefits that increase productivity and provide opportunities for new kinds of experiments:

Feature Benefit
>0.5 nA current in an atom-sized probe Rapid atomic-resolution EELS elemental mapping
Correction of all fifth-order axial aberrations Larger probe angles, higher beam current
Every operation can be performed remotely Remote operation with no local assistance
Computer-controlled sample exchange Samples can be changed by remote users
Up to 5 samples stored in storage chamber Rapid sample change – no waiting for vacuum to recover
Friction-free, centro-symmetric sample stage Ultra-precise sample motion, freedom from drift
Double tilt holder with ball bearing mechanics Ultra-precise sample tilting
Fast electrostatic beam blanker Avoids sample damage when not collecting data
3rd-order-corrected EELS coupling optics >50 mr acceptance semi-angles, more efficient analysis
Optional pre-corrector scanning Aberration-corrected conical illumination scanning
Microscope column is entirely ion-pumped Minimizes sample contamination and etching
Column uses only metal vacuum seals Sample vacuum typically <1x10-9 torr
Whole column bakeable to 140°C Eliminates microscope-caused contamination
Double μ-metal shielding of entire column Minimizes sensitivity to stray AC fields
Completely modular construction Column can be reconfigured after installation
Self-diagnosing electronics Rapid remote servicing


Nion's Ultra-High Energy Resolution Monochromated EELS-STEM combines our monochromator and spectrometer to achieve energy resolutions of < 6 meV (at 60kV). It offers high energy dispersion up to 0.1 meV/channel (at 60 kV), and a large energy range of up to 1 keV at 60 kV and beyond 2 keV at 200 kV. Energy drift is less than 5 meV / minute, providing excellent long-term stability.

The HERMES can be built around either beam source used in UltraSTEM systems, either Nion's 200 kV CFEG or the VG 100 kV gun.

Nion UltraSTEM 200

This electron microscope extends the range of operating voltages of the Nion microscopes to 200 kV. Its column is similar to the UltraSTEM 100, but it uses a new, high brightness/high stability cold field emission gun developed by Nion.

The gun features several new design elements that allow operation at lower voltages at performance levels similar to guns optimized to function only at the lower voltage.

The higher operating voltage gives:

  • higher resolution: 0.8 Å high angle dark field resolution (HAADF)
  • higher probe current: > 1 nA in a 2 Å probe
  • greater sample penetration

HAADF image of multiply twinned gold crystal particles (800x1200 pixel sub-area of a 2048x2048 image is shown). UltraSTEM200 operating at 200 kV. Many fine spacings in the particles and well resolved single atoms lying next to the particles can be seen. The insert shows the Fourier transform of the whole image.

Nion UltraSTEM 100

Medium angle annular dark field (MAADF) images of the edge of graphene, taken 2 minutes apart. Note the extensive rearrangement that occurred at the edge, and the heavier adatom (probably Al) dangling off the edge. Single arrows in4 (a) show five-fold C rings, the double arrow shows a single atom of C dangling off the edge. Nion UltraSTEM 100, 60 keV. (Krivanek et al., Ultramicroscopy 110 (2010) 935-945)

UltraSTEM column

The UltraSTEM 100 is a high-performance dedicated scanning-transmission electron microscope (STEM) with many unique features. Its flexible column provides < 1 Å resolution imaging as well as rapid nanoanalysis with an atom-sized electron probe containing > 0.5 nA of current, and efficient coupling into a variety of detectors. It can also produce high-quality diffraction patterns and even CTEM images.

The UltraSTEM has produced atomic-resolution elemental maps in less than a minute (see results). This promises to lead to a new era in electron microscopy in which atomic-resolution elemental maps become a powerful addition to the range of available microscopy techniques. It has also produced unsurpassed images of graphene and similar light-Z materials, while operating at 60 keV, below the knock threshold for C and other light atoms.

The principal design elements of the UltraSTEM that have made this advance possible are:

  • high-brightness cold field emission electron gun (CFEG)
  • high-performance 3rd generation C3/C5 aberration corrector
  • ultra-stable sample stage using detachable sample cartridges
  • optimized EELS coupling optics
  • UHV construction
  • complete remote operability, including sample exchange

Many of these features are unique to the Nion microscope. A full description of the microscope was published in Ultramicroscopy.

Custom solutions

Nion is a small and responsive company whose scientists and engineers are deeply knowledgeable about electron microscopes and very interested in pursuing new applications. Our UltraSTEM microscopes are completely modular; all the modules of the microscope column use the same exact mating surface. They can therefore be stacked in almost any sequence and total number. The vacuum system, the electronics, and the detector column are also modular. This means that the column can be reconfigured in many different and unique configurations.

Nion Service

The service of Nion microscopes is based on four principles:

  • Remote diagnosis. The Nion microscope is completely remotely operable. If a problem appears, Nion personnel typically diagnose it by operating the microscope remotely, within 24 hours of the problem being reported.
  • Modularity. Because the microscope is modular, the number of different types of spare parts (PCBs, cables, mechanical modules) is minimized. Nion is typically able to ship a replacement for a defective module that can be installed by the customer within 24 hours of the diagnosis becoming clear.
  • Site Service. More challenging problems requiring an on-the-spot intervention are typically resolved with a visit by the Nion expert specializing in that particular subsystem. Customers therefore do not have to go through several visits by service engineers who are not sufficiently familiar with the full complexities of the microscope and end up passing the problem onto a higher level in the service organization.
  • Update visits. As a part of the Nion service plan, Nion engineers visit the site at least once a year to carry out major software updates and customer training refreshers.