The facility provides a world-leading capability for the direct imaging of atomic structures as well as the determination of elemental composition, along with chemical and bonding analysis down to single atom precision. As such it supports the elucidation of structure-property relationships in advanced materials and devices for the benefit of the scientific user community, stemming from fields as diverse as condensed matter physics, catalysis, bio-materials research, chemistry, mineralogy, nuclear materials research among many others.
In light of its international success over a period of over 15 years, the funding to support the SuperSTEM facility and its staff scientists has recently been renewed by the Engineering and Physical Sciences Research Council (EPSRC) for a further period of 5 years with a new contract worth more than £7 million, starting March 2017.
SuperSTEM has gathered a team of world-leading experts in the field of scanning transmission electron microscopy and energy loss spectroscopy who, in addition to being dedicated to assisting facility users and collaborators with their data acquisition, data processing and modelling, are also developing their own research programmes.
SuperSTEM is located in a purpose-designed building housing three state-of-the-art aberration corrected STEM instruments on the SciTech Daresbury Science and Innovation Campus on the outskirts of Warrington. The facility is embedded within the UK academic community through a consortium of universities consisting of the Universities of Glasgow, Leeds, Liverpool, Manchester, Oxford and York, with further close links with a wide network of collaborators and academic institutions.
Access to SuperSTEM
is free at the point of use for UK researchers as well as their worldwide collaborators, for short-term of proof-of-principle projects. Other access, including long-term projects, is normally subject to funding through grant proposals. We also welcome applications from commercial institutions, please contact us for commercial rates.
SuperSTEM specialises in multi-modal analytical microscopy, going beyond simple imaging thanks to the laboratory’s widely recognised expertise in electron energy loss (EEL) and energy dispersive X-ray (EDX) spectroscopies. In particular, the facility’s most recent instrument, a Nion UltraSTEM100MC boasts one of the world’s highest energy resolutions, enabling capabilities such as vibrational spectroscopy or band gap mapping at the nanometre scale.
Further modes of operation supported by the facility include diffractive imaging (also known as 4D STEM), and in-situ electro-thermal testing of nano-scale materials (thanks to dedicated holders). As part of its recently renewed contract with EPSRC, the facility is in the process of planning a significant infrastructure investment to develop its on-site sample preparation and materials nanofabrication expertise, with the aim to provide ultra-thin, damage-free specimens optimised for atomic-resolution STEM imaging and analysis.
To fully benefit from aberration correction all other impeding factors such as mechanical vibrations, temperature oscillations, humidity or electromagnetic interference have to be minimized.
The chosen site for SuperSTEM at the STFC Daresbury Laboratories has excellent geological stability due to a sandstone bedrock with stratified rocks. The building itself was designed to minimise vibrations by separating the foundations of the microscope rooms from the main building foundations ("house-in-house" concept). This structure also provides excellent accoustical isolation and damping.
In addition, electrical wiring designed to minimise interference, separate electrical supplies, computer-controlled air handling, close temperature control and air conditioning with low long term oscillation characteristics ensure reliable microscopy.
Cross sections showing the foundations of the SuperSTEM rooms
History of SuperSTEM
The SuperSTEM project began in 1997 when Prof. Mick Brown presented a paper at the EMAG conference in Cambridge entitled "A Synchrotron in a Microscope". He challenged the UK microscopy community to pool resources to exploit the emerging technology of spherical aberration correction.
Prof. Ondrej Krivanek, one of the pioneers in the field, had recently returned to Cambridge to work with Prof. Brown in the Microstructural Physics group and had successfully developed a prototype corrector for STEM. Building on this breakthrough, the SuperSTEM project was funded by the Engineering and Physical Sciences Research Council (EPSRC) in 2001 with the goal to realise Prof. Brown's vision. By that stage, it consisted of lead scientists from the Universities of Liverpool, Cambridge and Leeds with Prof. Peter Goodhew as the principal investigator and Prof. Andrew Bleloch as its director. The final makeup was largely serendipitous because the project had had strong support from a large number of people and organisations and with the addition of Glasgow University it has proved a very effective team.
SuperSTEM was the first facility in Europe to adopt aberration correction by incorporating a Nion quadrupole-octupole correction system into a VG STEM as early as spring 2002.
The First Instrument
The first instrument (SuperSTEM1) is based on the Cambridge VG HB 501UX dedicated STEM, which was retro-fitted with a Nion MkII quadrupole-octupole aberration corrector, an improved design from the prototype developed at Cambridge by Prof. Krivanek.
As a result the spatial resolution was doubled from ~2 Å to below 1 Å.
The Second Instrument
Many new and important results have been obtained on this microscope but from the beginning it was clear that the 30 year old design of the VG microscopes was not optimised for aberration correction. Nion's response was to build an entirely new microscope, the UltraSTEM™ 100, that overcame these difficulties. SuperSTEM2 was the first such instrument in use for scientific research.
It provides sub-Angstrom resolution with 5th order aberration correction, while its electron optical system provides great flexibility for applications such as electron energy loss elemental mapping at atomic resolution or diffractive imaging. A silicon drift EDX detector was recently fitted with a view to provide simultaneous X-ray and EELS mapping capabilities.
The Third Instrument
A new revolution is in the making at SuperSTEM, with the installation of the new and unique electron microscope, UltraSTEM 100 MC ‘HERMES’ in 2015.
The new instrument, SuperSTEM3, one of only four monochromated Nion electron microscopes in existence, boasts the world's highest energy resolution at a mere 10meV, along with the highest spatial resolution for a microscope operating in this energy range (0.1nm at 60kV, 0.08nm at 100kV). This energy resolution is the foundation of truly ground-breaking capabilities, enabling capabilities such as vibrational spectroscopy or band gap mapping at the nanometre scale.
This instrument has the potential to shift the paradigm of electron microscopy from "telling what atoms are where", to "telling what atoms are where, how these atoms are bonded to each other and what this bond might mean for their electronicconfiguration and therefore the macroscopic properties of the device they are used for".
Crucially, SuperSTEM3 is the only such instrument fully available to the U.K. and worldwide scientific community, as part of the open-access user facility funded by EPSRC. It’s installation marks yet another world first for the SuperSTEM Laboratory and it will strengthen its status as one of the premier centres for electron microscopy and spectroscopy in the world.