News



Robust core-loss EELS modeling of doped  graphene
5/5/2017
Electron energy loss spectroscopy (EELS) in a STEM microscope is possibly the most powerful analytical tool  for understanding the chemical and electronic structure of materials down to the atomic level. However,  direct interpretation of the spectra is more than often not trivial. The ability of accurately and quantitatively modelling the EELS response is essential in undertanding experimental results.
 
In a  paper, recently published in the Journal of Physics: Condensed Matter   members of SuperSTEM in collaboration with the University of Leeds explore some of the challenges in theoretical density functional theory (DFT) calculations of 1s core-level EEL K-edge spectra of pure, B-doped and N-doped graphene are explored.  The ground state approximation is found in this specific system to perform consistently better than the commonly used frozen core-hole approximation. The impact of including or excluding a core-hole on the resultant theoretical band structures, densities of states, electron densities and EEL spectra were all thoroughly examined and compared. It is concluded that the frozen core-hole approximation exaggerates the effects of the core-hole in graphene and should be discarded in favour of the ground state approximation. These results are interpreted as an indicator of the overriding need for theorists to embrace many-body effects in the pursuit of accuracy in theoretical spectroscopy instead of a system-tailored approach whose approximations are selected empirically.
 
The results appear in:  
 
T.P. Hardcastle, et-al, Robust theoretical modelling of core ionisation edges for quantitative electron energy loss spectroscopy of B- and N-doped graphene, J. Phys.: Condens. Matter 29 (2017) 225303
 
More details: https://doi.org/10.1088/1361-648X/aa6c4f
 


Undestanding the origin of reduced magnetization in magnetite nanoparticles
20/4/2017

Magnetite nanoparticles are partiularly sought after for many technological such as  magnetic sensors,
 magnetic storage media, MR imaging, but also biomedical applications such as magnetic resonance imaging, targeted drug delvely and cancer treatment. The functionality of the nanoparticles for applications depends crucially on the magnetic properties.  Researchers from the Universities of York and  Carnegie Mellon Univeristy in collaboration wth SuperSTEM, demonstate how the presence of structural defects such as antiphase boundaries in small magnetite nanoparticles lead to signficantly reduced magnetization, relative to the bulk. Atomistic magnetic modelling of nanoparticles with and without these defects reveals the origin of the reduced moment. Strong antiferromagnetic interactions across antiphase boundaries support multiple magnetic domains even in particles as small as 12-14 nm.


The results appear in Scientific Reports

Z. Nedelkoski, D. Kepaptsoglou, et-al.,  Origin of reduced magnetization and domain formation in small magnetite nanoparticles, Scientific Reports 7 (2017) 45997 


 




Unravelling the functionality of high performance thermoelectric oxides in Chemistry of Materials
07/11/2016

In the search for clean and renewable energy, thermoelectric oxides emerge as dependable and cheap sources of producing electricity from waste heat. Sr doped Bismuth Cobaltate (BSCO) is one of the best p-type thermoelectric oxides but its structural and electronic properties are still poorly understood. By combining experimental and  computational approachs researchers from  the Universities of Bath and Manchester in collaboration with SuperSTEM, shed light into the electronic transport mechanism of BSCO. The study shows that level of Bi deficiency in the rock-salt layers,leads to a band gap opening and increases p-type electronic conductivity due to the formation of Co4+ species that serve  as itinerant holes within the predominantly Co3+ framework of the CoO2 layer. These atomicscale  structural and electronic structure modifications are in turn responsible for the high positive Seebeck coefficient of the material measured experimentally. This provides another step  in understanding this fascinating material, which should be of great benefit in future design of oxide thermoelectric materials that are composed of inexpensive and abundant elements. 
 
The results were published in Chemistry of Materials earlier this month. 

J.D. Baran, D. Kepaptsoglou, M. Molinari, et al, Role of Structure and Defect Chemistry in High-Performance Thermoelectric Bismuth Strontium Cobalt Oxides, Chemistry of Materials 28 (2016)  7470–7478
 
More details: http://dx.doi.org/10.1021/acs.chemmater.6b03200

 






Advanced techniques for visualising plasmons and understanding their interaction with molecular systems reviewed.
07/08/2016

SuperSTEM staff members Patricia Abellan, Fredrik Hage, Quentin Ramasse and former SuperSTEM staff Ruth Chantry contributed to 2 invited reviews in the emerging investigator issue of Analyst and in Advances in Physics: X, in collaboration with Patrick El-Khoury and a research team from Pacific Northwest National Laboratory (PNNL). These two reviews highlight different techniques employed to visualize the enhanced electric fields associated with surface plasmons, and to probe various aspects of the immediate local environments surrounding individual molecules. Through select practical examples from the two laboratories, the team discussed how localized and propagating surface plasmons can be visualized at the ultimate space, time and energy limits using various techniques powered by photons, photoelectrons, and electrons. The prospects of characterizing either bare or chemically functionalized plasmonic nanostructures through a combination of the various described techniques are discussed in the two references provided below. 



P. Z. El-Khoury, P. Abellan, Y. Gong, F. S. Hage, J. Cottom, A. G. Joly, R. Brydson, Q. M. Ramasse and W. P. Hess, Visualizing surface plasmons with photons, photoelectrons, and electrons, Analyst, DOI: 10.1039/C6AN00308G  (2016)

P.Z. El-Khoury, P. Abellan, R.L. Chantry, Y. Gong, A.G. Joly, I. V. Novikova, J. E. Evans, E. Aprà, D. Hu, Q. M. Ramasse & W.P. Hess, The information content in single-molecule Raman nanoscopy, Advances in Physics X (2016)  DOI: 10.1080/23746149.2016.1140010 .







SuperSTEM welcomed schools and families during the Daresbury Open Week

9/07/2016

SuperSTEM opened the doors to visitors on 7th July and 9th July. Thursday’s event was dedicated to Key Stages 4 and 5 students and included talks and demonstrations in SuperSTEM 2. During the busiest day of the Daresbury Open Week, the public day on Saturday 9 July, the Science & Technology Facilities Council (STFC) estimates that more than 7,500 people came to Sci-Tech Daresbury. General public, families and members of different laboratories at Sci-Tech Daresbury were welcome to tour SuperSTEM, which included a visit to the newest monochromated instrument, life demonstration in SuperSTEM 2, outdoors posters, an interactive virtual microscope demonstrations and videos for the youngest ones and an introduction about SuperSTEM scope and its role within the scientific community.

[http://www.stfc.ac.uk/news/dl-open-week/]



 


Towards direct badgap Ge1-xSnx nanowires: non-equilibrium grown process reported in Nature Communications.
21/05/2016
  
The development of non-equilibrium group IV nanoscale alloys is critical to achieving new functionalities, such as the formation of a direct bandgap in a conventional indirect bandgap elemental semiconductor. Subhakit Biswas, Jessica Doherty and their co-workers from Prof. Justin Holmes’ group at University College Cork describe the fabrication of uniform diameter, direct bandgap Ge1-xSnx alloy nanowires with a Sn incorporation far in excess of the equilibrium solubility of Sn in bulk Ge, through a conventional catalytic bottom-up growth paradigm using noble metal and metal alloy catalysts. STEM-EELS mapping carried out on SuperSTEM 2 in collaboration with SuperSTEM’s Quentin Ramasse was instrumental in determining the distribution of Ge and Sn within the wires, as well as the quality of the interface with the metal seed particles, both essential to the physical properties of the heterostructure wire. The results were published in Nature Communications earlier this month. 



S. Biswas, J. Doherty, D. Saladhukha et al., Non-equilibrium induction of tin in germanium: towards direct bandgap Ge1-xSnx semi-conductors, Nature Communications 7, 11405 (2016). DOI: 10.1038/ncomms11405  






Breakthrough in controlling the removal of structural defects in chalcogenides absorber thin films for high efficiency solar cells reported in Energy and Environmental Science.
11/05/2016
  
The development of thin-film solar cells has been a success story in recent years in terms of record efficiencies in the lab. Single junction solar cells based on compound semiconductor films have reached higher energy-conversion efficiencies than polycrystalline silicon. Despite this success and the prospects of novel applications such as flexible, lightweight solar panels, the market share of thin-film solar modules is stagnating. A major problem of compound thin-film solar cells, such as Cu(In,Ga)Se2, is the large gap between lab efficiencies and commercial module efficiencies. A large process parameter space makes trial-and-error optimization a time-consuming and expensive task. Therefore, understanding the underlying atomic-scale physics and chemistry is essential to identify the potential origins of efficiency losses in the transfer from lab- to large-scale fabrication. In this contribution results from an international collaboration including the SuperSTEM Laboratory provide direct insight into defect formation and annihilation during the fabrication of Cu(In,Ga)Se2 films. Consequences for process optimization and design are proposed. The presented approach can also be applied to understand other thin-film fabrication processes.


R. Mainz, E. Simsek Sanli, H. Strange et al., Annihilation of structural defects in chalcogenide absorber films for high-efficiency solar cells, Energy and Environmental Science (2016). DOI:10.1039/c6ee00402d  






Solvents to Slow Down In Situ Synthesis: A method for creating net molecular hydrogen environment to form homogeneous metal particles in the STEM discussed in Langmuir
18/04/2016
By synthesizing nanomaterials of uniform shape and size, the novel properties of metals arising at the nanoscale can be accessed and the fundamental investigation of their structure-property relationships enabled. SuperSTEM’s Patricia Abellan and a team of scientists from Pacific Northwest National Laboratory in collaboration with Virginia Polytechnic Institute and State University, the University of California-San Diego and Florida State University have presented a new approach to synthesize Pd nanoparticles with homogeneous sub-3nm size by molecular hydrogen in the liquid cell. Molecular hydrogen is a widely used reductant in the synthesis of supported metal catalysts. Creating such suitable environment for in situ synthesis in the electron microscope was achieved by using toluene as the solvent and avoiding exposure of the solution to moisture. This work also aimed at finding new methods for reducing the production of radicals upon electron irradiation. Until now, this challenge has been addressed by lowering the amount of imaging electrons delivered to the liquid sample. This research looks at the problem from a different perspective and proposes the possibility of finding a suitable solvent, such as an aromatic hydrocarbon, which is inherently resistant to high energy electron irradiation, to reduce the overall production of radicals for the same electron dose applied.

P. Abellan, L.R. Parent, N. Al-Hasan, C. Park, I. Arslan, A.M. Karim, J.E. Evans and N.D. Browning, Langmuir201632, pp 1468–1477


 [http://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b04200
]



New Paper in Scientific Reports: Atomic and electronic structure of twin growth defects in magnetite
04/03/2016

In magnetic oxides any disturbance to the crystal structure is liable to significantly alter properties such as conductivity and magnetic ordering. The overall properties in those materials are strongly dependent on the local atomic co-ordination and structure due to the local nature of electron hopping mechanisms and super exchange interactions.
 
A team if scientists from the University of York in collaboration with the Tokyo Institute for Technology and SuperSTEM investigate the impact of stable twin defect in the magnetic properties Fe3O4 thin films. By using aberration corrected scanning transmission electron microscopy and spectroscopy and first principles calculations the sciestist look into the effect of the local atomic structural configuration of the twin boundary on the superexchange interactions between the two Fe sublattices across the twin grain boundary.  
 
More details: http://dx.doi.org/10.1038/srep20943

 


New Material Increases the Lifetime of Solar-Powered Electrons :Atom-by-atom control leads to an interface that sustains an internal electric field, an innovative property with promise in the energy conversion and storage
03/03/2016
Storing sunlight as fuel that can be later used to drive fuel cells requires new materials. A team of scientist from Pacific Nothwest National Laboratories in collaboration with scientists from SuperSTEM and the Univesity of Oxford has demonstrated that by careful desing interfaces between the oxide materials absorb visible light, producing electrons and holes that might be useful for catalyzing reactions, such as producing hydrogen fuel. If there is nothing to pull those electrons and holes apart, however, they will quickly destroy one another without doing anything useful. By synthesizing this material as a series of alternating layers, the team created a built-in electric field to separate the excited electrons and holes – openi ng new possibilities for better catalytic performance.  
Read more at http://www.pnnl.gov/science/highlights/highlight.asp?id=4208

http://dx.doi.org/10.1002/admi.201500779


 


Battery mystery solved: SuperSTEM scientists unravel structural ambiguities in lithium- and manganese-rich transition metal oxides in Nature Communications

30/10/2015
  
Using complementary microscopy and spectroscopy techniques, SuperSTEM Associate (and long-term visitor from LBNL) Alpesh Shukla reports in Nature Communications how he and colleagues, including SuperSTEM’s Quentin Ramasse and Fredrik Hage, solved the structure of lithium- and manganese-rich transition metal oxides, a potentially game-changing battery material and the subject of intense debate in the decade since it was discovered. This material is important because the battery capacity can potentially be doubled compared to the most commonly used Li-ion batteries today due to the extra lithium in the structure. Until today, however, scientists had been divided on whether the material structure is single trigonal phase, double phase, or defected single monoclinic phase. The new results give very strong support for the defected single-phase monoclinic model and appear to rule out the two-phase model.

A. Shukla, Q.M. Ramasse, C. Ophus, H. Duncan, F. Hage and G. Chen, Unravelling structural ambiguities in lithium- and manganese-rich transition metal oxides, Nature Communications 6, 8711 (2015).  



[http://dx.doi.org/10.1038/ncomms9711
]




The new graphene? Liquid-exfoliated black phosphorus in Nature Communications

18/10/2015
  
SuperSTEM collaborators at Trinity College Dublin have demonstrated the successful chemical exfoliation of few-layers solvent-stabilized black phosphorus, a new two-dimensional material which is of great interest for applications, mainly in electronics. Thanks to the use of specific solvents during the exfoliation, Damien Hanlon and co-workers were able to mitigate the normally very rapid structural deterioration of this material, enabling its visualization with atomic resolution using SuperSTEM’s microscropes. The study, published in Nature Communications, also demonstrates that liquid-exfoliated BP nanosheets are potentially useful in a range of applications from ultrafast saturable absorbers to gas sensors to fillers for composite reinforcement.

D. Hanlon, C. Backes, E. Doherty, C.S. Cucinotta, N.C. Berner, C. Boland, K. Lee, A. Harvey, P. Lynch, Z. Gholamvand, S. Zhang, K. Wang, G. Moynihan, A. Pokle, Q.M. Ramasse, N. McEvoy, W.J. Blau, J. Wang, G. Abellan, F. Hauke, A. Hirsch, S. Sanvito, D.D. O’Regan, G.S. Duesberg, V. Nicolosi and J.N. Coleman, Liquid exfoliation of solvent-stabilized few-layer black phosphorus for applications beyond electronics, Nature Communications 6, 8563 (2015). 



[http://dx.doi.org/10.1038/ncomms9563
]




Spectroscopic signature of doping in graphene

05/10/2015
 
SuperSTEM researchers in collaboration with researchers from the Universities of Leeds, Manchester and Gottingen investigate the electronic structure modifications incurred by free-standing graphene through two types of single-atom doping. Trough careful comparison with density functional theory calculations the researchers show that EELS spectra acquired from single B or N dopants can be used as direct fingerprints of the expected p- and n-type behaviour of doped graphene.

D.M. Kepaptsoglou, T.P. Hardcastle, C.R. Seabourne, U. Bangert, R. Zan, J.A. Amani, H. Hofsass, R.J. Nicholls, R. Brydson, A.J. Scott and Q.M. Ramasse, Electronic structure modification of ion-implanted graphene: the scpectroscopic signatures of p- and n-type doping, ACS Nano, Articles ASAP (2015).

[http://pubs.acs.org/doi/abs/10.1021/acsnano.5b05305
10.1111/jmi.12290]





Atoms in close-up: SuperSTEM features in Cosmos Magazine

31/08/2015


Australia's renowed Cosmos magazine features SuperSTEM research in its look at the building blocks of matter:



What nanoparticulate dispersions look like: review article in Journal of Microscopy
12/08/2015

Prof. Rik Brydson and researchers from the University of Leeds were invited by the editors of Journal of Microscopy to review the most common methods for determining the dispersion state of nanoparticulate samples, particularly in liquid media. The team and their collaborators, including SuperSTEM staff Patricia Abellan focused on the determination of particle sizes and shapes as well as particle structure and chemistry, key parameters for understanding their behaviour applied across a very wide range of technologies and industry sectors. The review highlights the potential contributions of scanning probe and electron microscopies and also includes an extensive table summarising the major non-microscopy techniques employed to analyse particulate dispersions.



R. Brydson, A. Brown, C. Hodges, P. Abellan and N. HondowMicroscopy of Nanoparticulate Dispersions, Journal of Microscopy, Journal of Microscopy, Articles ASAP, doi: 10.1111/jmi.12290
 (2015). 

[http://dx.doi.org/1
10.1111/jmi.12290]




New paper in Nano Letters: electrical nature of nano-contacts
23/06/2015

A recent paper in Nano Letters by Alex Lord and co-workers from the University of Swansea explores the electrical behaviour of nanocontacts between free-standing ZnO nanowires and the catalytic Au particles used for their growth, showing how the nature of the contact can switch from Schottky to Ohmic depending on the size of the particles in relation to the cross-sectional width of the nanowires. Instrumental to this study were results obtained in collaboration with SuperSTEM staff Quentin Ramasse and Demie Kepaptsoglou. 




A.M. Lord, T.G. Maffeis, O. Kryvchenkova, R.J. Cobley, K. Kalna, D.M. Kepaptsoglou, Q.M. Ramasse, A.S. Walton, M.B. Ward, J. Köble and S.P. Wilks, Controlling the electrical transport properties of nanocontacts to nanowires, Nano Letters, Articles ASAP, doi: 10.1021/nl503743t (2015). 

[http://dx.doi.org/1
10.1021/nl503743t]




Farewell to Mervyn Shannon
01/06/2015

After more than 12 years on the SuperSTEM team as Industrial Director, co-Director and on-site Director, Professor Mervyn Shannon recently announced his decision to take an early retirement. An avid traveler and rambler, Mervyn will no doubt spend a fair amount of his extra free time hiking here and abroad, using the high-tech walking poles (graphene re-inforced!) the team bought him as part of his farewell present. But his association with SuperSTEM will not end so abruptly: as honorary Visiting Professor at the University of Liverpool, he will still be coming to the lab very regularly to keep up with new projects and to work on his own research, as a hobby. We wish him all the best!

                              
Pictures from the farewell party at our favourite curry house in Stockton Heath, with special guests Ondrej Krivanek and Niklas Dellby.


New paper in Nature Communications: magnetic phase gradients at complex oxides interfaces
17/04/2015

New research highlight! SuperSTEM user Steven Spurgeon uses atomic-resolution STEM-EELS results obtained in collaboration with on-site staff Demie Kepaptsoglou and Quentin Ramasse to show how a magnetic asymmetry observed at the La0.7Sr0.3MnO3 (LSMO)/PbZr0.2Ti0.8O3 (PZT) interface depends on the local PZT polarization and gives rise to gradients in local magnetic moments. The full details have just been published in Nature Communications.


S.R. Spurgeon, P.V. Balachandran, D.M. Kepaptsoglou, A.R. Damodaran, C.L. Johnson, J. Karthik, S. Nejati, L. Jones, H. Ambaye, V. Lauter, Q.M. Ramasse, K.S. Lau, J.M. Rondinelli, L.W. Martin and M.L. Taheri, Polarization screening-induced magnetic phase gradients at complex oxide interfaces, Nature Communications 6, 6735 (2015).

[http://dx.doi.org/
10.1038/ncomms7735]


SuperSTEM looks back at a successful SuperSTEM 3 inauguration
02/03/2015

Over 120 guests joined the SuperSTEM team and EPSRC to celebrate the installation on STFC's Daresbury Scientific Campus of the facility's new state-of-the-art monochromated Nion Hermes microscope during a hugely successful two-day international workshop.
 

World-renowned speakers delivered inspiring scientific lectures and provided their views and hopes for what scientists might
be able to achieve with this new generation of electron microscope. The "excitement of the unknown", prospects for "mapping phonons and other low energy excitations" were systematic topics of discussion during the lectures, over coffee and late into the night after the gala dinner. These are exciting times for electron microscopy, and with the unprecedented <15meV resolution this instrument already achieves a mere 3 weeks after its arrival on site (in boxes), Prof. Archie Howie's hope to "lure physicists back into electron microscopy to tackle the experimental and theoretical challenges posed by such capabilities" may soon come true.
Read more on our events page.




The installation of the new SuperSTEM 3 is in full swing - and it's big!
26/01/2015
   
   


Proud to announce the delivery of our new SSTEM3 microscope!!!
20/01/2015

A very cold (the outside temperature is barely reaching 0 deg C) but very exciting day for SuperSTEM. The much anticipated Nion UtraSTEM100MC ("HERMES") microscope is finally delivered on site! 

 


A late Christmas present: new microscope shipping from the factory!
13/01/2015

Happy New year to all our SuperSTEM users and collaborators: and what better way to start the New Year than with a late Christmas present? Our new microscope, a Nion UltraSTEM100MC ("HERMES") is now on its way from the factory and will be installed and commissioned over the next few weeks in its new custom-designed room at SuperSTEM.
Stay tuned for more news of the installation!! For now, here is a picture of the crates (without wrapping paper or a little bow :( ) waiting to be picked up for shipment outside Nion Co. (photo courtesy of Nion scientist Tracy Lovejoy).
 



Summary of SuperSTEM User Survey
12/01/2015

Thanks to everyone who took the time to complete the survey.  Generally you were very supportive of our work to date and of the additional aspects regarding sample preparation, data processing and modelling that we asked about.

Your views were briefly summarised and included in the Statement of Need we submitted to EPSRC on 15 October for the continuation of a Mid-Range Facility for Aberration-Corrected STEM from 2016 - 2021. 

A detailed summary of the survey can be found here.


 



Welcome to new staff scientists!
27/11/14

SuperSTEM extends a heartfelt welcome to three new staff scientists: Dr Patricia Abellan, Dr Ruth Chantry and Dr David Hernandez.

This enlargement of the SuperSTEM group together with the imminent delivery of our third aberration corrected instrument opens up new prospects of research at SuperSTEM.



Farewell to Tim Pennycook
30/10/14

SuperSTEM staff scientist Tim Pennycook has moved on to work with the Physics of Nanostructured Materials Group at the University of Vienna.
We wish him all the best!


Good Vibrations: Nature letter on vibrational spectroscopy in Nion HERMES
09/10/2014

In today's issue of Nature, Krivanek et al report on the new capabilities that the Nion HERMES will bring to electron microscopy: vibrational spectroscopy at high spatial resolution at features such as interfaces, grain boundaries, surfaces, nanoparticles; hydrogen detection for the first time in electron microscopy; aloof beam studies of beam sensitive materials.

Of course this is the instrument that will be delivered to SuperSTEM later this year (see Launch Event below).  So come and join us at this event to learn more about the science it will enable.

[http://dx.doi.org/10.1038/nature13870]

See also the News and Views item "Materials Analysis: Good Vibrations" written by Rik Brydson:

[http://dx.doi.org/10.1038/514177a]

 

New paper in PNAS: Organic synthesis in extraterrestrial dust
07/10/2014

Lead author Christian Vollmer (Universitat  Munster) collaborating with SuperSTEM staff  Demie Kepaptsoglou and Quentin Ramasse, as well as researchers from the the Max-Planck-Institut für Chemie, 
University of Manchester and Carnegie Institution of Washington, investigate the origin of pristine organic matter located in primitive extraterrestrial samples, such as meteorites . The authors show that this pristine matter   - among the most primitive organic molecules that were delivered to the early Earth 4.5 billion years ago - contains  highly aromatic and nitrogen-containing  organics,  transformed rom an oxygen-rich organic reservoir by parent body fluidsynthesis in the early solar system.

C. Vollmer, D. Kepaptsoglou, J. Leitner, H. Busemann, N.H. Spring, Q.M. Ramasse, P. Hoppe and L.N. Nittler, Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites, Proceedings of the National Academy of Sciences of the United States of America,
[http://dx.doi.org/1
10.1073/pnas.1408206111]

Launch Event for SuperSTEM 3 - Nion HERMES monochromated, aberration-corrected STEM
07/10/2014

A Launch Meeting is being organised by EPSRC and SuperSTEM for the 19th and 20th of February 2015 at Daresbury Laboratory to celebrate the installation of the third SuperSTEM instrument, a Nion HERMES.

This instrument will boast <10meV energy resolution enabling phonon spectroscopy with atomic scale resolution, enhanced band gap measurements, etc...  It will also offer improved spatial resolution at 60kV and lower voltages.

After a  formal opening on the morning of 19 February there will be a seminar until lunchtime on 20 February.  Watch this space for news of the speakers and programme and how to register for the meeting.
 

New paper in PRL: moving silicon atoms with atomic precision
16/09/2014

Lead author Toma Susi (University of Vienna) collaborating with SuperSTEM staff Quentin Ramasse and Demie Kepaptsoglou, as well as researchers at the University of Manchester, Nion Co. and at the University of Vienna, study the motion of single Si atoms substituted in graphene when irradiated by a 60kV electron beam in their latest paper in Physical Review Letters. They shed light on a fascinating silicon-carbon bond inversion mechanism that could provide the ability to move substitutional dopants in graphene with atomic precision.

T. Susi, J. Kotakoski, D.M. Kepaptsoglou, C. Mangler, T.C. Lovejoy, O.L. Krivanek, P. Ayala, J. Meyer and Q.M. Ramasse, Silicon-carbon bond inversions driven by 60 keV electrons in graphene, Physical Review Letters, [http://dx.doi.org/110.1103/PhysRevLett.113.115501]



NEW!! SuperSTEM Staff Scientist position available
20/08/2014
 
A SuperSTEM Staff Scientist post is available to provide research leadership and user support at the SuperSTEM Laboratory, the EPSRC UK National Facility for Aberration-Corrected Scanning Transmission Electron Microscopy (STEM) http://www.superstem.org/. Based at the STFC Daresbury Laboratory, the post will be associated with the Department of Materials at the University of Oxford




The SuperSTEM Staff Scientist will undertake and lead aspects of research associated with aberration-corrected STEM machines, providing user support, contributing to the development of techniques and research funding applications, responsible for aspects of equipment maintenance and development, and undertaking administration and teaching as required.
The post is available immediately for a fixed-term of up to 24 months. Applicants should have a PhD in Physics, Materials, Engineering, Biology or a related field, or equivalent experience, with significant postdoctoral research experience in advanced electron microscopy.

The closing date for applications is 12.00 midday on 24 September 2014 with interviews currently planned for 15 October 2014.

https://www.recruit.ox.ac.uk/pls/hrisliverecruit/erq_jobspec_version_4.jobspec?p_id=114770

Please contact Prof. Quentin Ramasse (qmramasse@superstem.org) or Prof. Pete Nellist (peter.nellist@materials.ox.ac.uk) for informal inquiries. 


Promoting a cleaner planet: work on MoS2 to appear on the cover of Angewandte Chemie
15/08/2014
 
SuperSTEM user Yuanyuan Zhu and scientific director Quentin Ramasse determined the stoichiometry of the catalytically important edge sites in single layer MoS2 nano-catalysts, atom by atom, visualising in particular the position of cobalt promoter atoms. These insights should facilitate the optimisation of methods for MoS2 nanocatalyst preparation. This work was carried out as part a highly successful collaboration between SuperSTEM, Lawrence Berkeley National Laboratory and Haldor Topsøe A/S, which has now yielded three successive covers of Angewandte Chemie! 

Y. Zhu, Q.M. Ramasse, M. Brorson, P.G. Moses, L.P. Hansen, C.F. Kisielowski and S. Helveg, Angew. Chem. Int. Ed. 53 (2014), Early view article [http://dx.doi.org/10.1002/anie.201405690]


SuperSTEM Summer School a great success!!
29/07/2014
 
Many thanks to all the participants and lecturers for making this year's Summer School a great success. We all thoroughly enjoyed welcoming you at the lab for these four days packed with lectures and social events and we hope to see you all soon in the future.
Watch this space for information on our next Summer School in two years' time.

The 6th biennial SuperSTEM Summer School on Advanced Topics in Aberration-Corrected STEM was possible thanks to generous contributions from ESTEEM2, EMS, HREM Research, Nion Co., Bruker and EPSRC.

Read more




Cu- and Ag-rich precipitates in Al-Mg-Si-Cu-Ag alloys revealed at atomic resolution
27/07/2014
 
A paper recently published in Scripta Materialia by SuperSTEM user Sigurd Wenner, from NTNU in Trondheim, in collaboration with staff members Demie Kepaptsoglou, Fredrik Hage and Quentin Ramasse, reveals the distribution of Cu and Ag columns in Cu- and Ag-rich precipitates in an Al–Mg–Si–Cu–Ag alloy.

S. Wenner, C.D. Marioara, Q.M. Ramasse, D.M. Kepaptsoglou, F.S. Hage and R. Holmestad, Scripta Materialia 74 (2014) 92–95. [http://dx.doi.org/10.1016/j.scriptamat.2013.11.007]

SuperSTEM Research Fellow Vacancy
21/07/2014

A SuperSTEM Research Fellow/Staff Scientist position has been created to provide research leadership and user support at the SuperSTEM Laboratory, the EPSRC UK National Facility for Aberration-Corrected Scanning Transmission Electron Microscopy.  

The post is based at the SuperSTEM Laboratory at Daresbury with appropriate visits to the School of Process, Environmental and Materials Engineering at the University of Leeds and other partner or collaborator institutions. The post holder will be responsible for aspects of equipment maintenance/development and undertake and lead aspects of research associated with aberration-corrected scanning transmission electron microscopy (STEM), to provide user support at a user facility, to contribute to the development of techniques, to contribute to gaining research funding, and to undertake administration and other teaching as requested by the Principal Investigator or Head of School.

The SuperSTEM Laboratory is situated at the Daresbury Science and Innovation Campus in Cheshire. It is the main site of the UK EPSRC National Aberration-Corrected STEM Facility. This is managed by a consortium of the Universities of Leeds, Oxford, Manchester, Liverpool and Glasgow. In 2012 SuperSTEM was awarded the contract to provide the National Facility for Aberration Corrected Scanning Transmission Electron Microscopy until September 2016. 

The Daresbury site houses two aberration corrected scanning transmission electron microscopes with electron energy loss spectroscopy systems, SuperSTEM I and SuperSTEM II. Both instruments have been installed for several years and provide a high performance platform for advanced research. In March 2012, the consortium was awarded funds to purchase SuperSTEM III (a Nion HERMES), which will have a monochromator and chromatic aberration corrector, in addition to the spherical aberration corrector. This is due for installation in autumn 2014. In addition the Consortium and Partner Universities have aberration-corrected instruments which provide additional functionality and these can be accessed via the National Facility. Further details can be found at www.superstem.com

A PhD in Physics, Materials, Engineering, Chemistry or a related field such as Biological Sciences, or equivalent experience is essential, as is a high level of expertise of the theory and practical experience of the operation of transmission electron microscopes.

Informal enquiries about the post may be made to Prof Rik Brydson, tel. +44 (0)11334 32369, email mtlrmdb@leeds.ac.uk.

University Grade 7 (£30,728 - £36,661 p.a.)

Further details can be found and application made via this link.  

Closing date: 13 August 2014.


‘The University of Leeds’ commitment to women in science has been recognised with a national accolade. The University and the Faculty of Engineering have received the Athena SWAN Bronze Award in recognition of our success in recruiting, retaining and developing/promoting women in Science, Engineering and Technology (SET).’ 

The University offers generous terms and conditions of employment, a wide range of benefits, services, facilities and family friendly policies. Full details are available on the Human Resources web pages.
Stepped anti-phase boundaries in Ti-doped Bi0.9Nd0.15FeO3
23/06/2014
 
A team of researchers at the Universities of Glasgow and Sheffield, in collaboration with SuperSTEM's Bernhard Schaffer and Quentin Ramasse, have just published a paper in APL Materials reporting on the atomic structure and chemistry of Fe-rich steps on antiphase boundaries in Ti-doped Bi0.9Nd0.15FeO3. These steps, studied using a combination of EELS and HAADF are also found to be negatively charged, resulting in a polarization of the surrounding matrix. 

I. MacLaren, L. Wang, A.J. Craven, Q.M. Ramasse, B. Schaffer, K. Kalantari and I.M. Reaney, APL Materials 2, 066106 (2014). [http://dx.doi.org/10.1063/1.4884684]






Happy Birthday Rik!
17/10/13

 

   
Despite best intentions the SuperSTEM team failed to surprise the chair of the executive committee with a birthday dinner.




SuperSTEM welcomes new staff scientist Dr Gareth Vaughan
27/09/13

 

   
SuperSTEM is pleased to announce that Dr Gareth Vaughan is joining the on-site team on October 1st.



Dr Budhika Mendis: the new SuperSTEM User Representative
06/09/13

 

   
Dr Budhika Mendis from the University of Durham was appointed as the SuperSTEM user representative at the SuperSTEM user meeting which took place during the EMAG conference in York, 3-6 September 2013. We are grateful for him to accept this position. Budhika was himself a SuperSTEM staff scientist from 2007 to 2008 and since then has returned to SuperSTEM periodically as a user of the facility. He can be contacted by email: b.g.mendis@durham.ac.uk.
  


New instrument casts its shadows before



Building works have started at SuperSTEM to erect an extension to the main building. The extension will house the new cutting-edge SSTEM III microscope, a Nion UltraSTEM 100 equipped with a monochromator. The new instrument will provide monochromation of the illuminating beam, chromatic aberration correction of the probe-forming beam and improved instrument stability.

Following the completion of the building works in the summer of 2013 and the delivery of the new instrument at the turn of the year, the enhanced capabilities of SSTEM III will be available for users in the first half of 2014.

 

 website contact: dorothea@superstem.org