SuperSTEM 2:
MAADF image of grain
boundary in Ba6-3xNd8+2xTi18O54
(BNT)
BNT is a highly
important material in mobile phone communication where it is used as
resonator/filter in base stations. Adjusting the material properties
of this material by varying composition necessitates a detailed
understanding of the atomic structure and changes with composition.
Atomic resolution imaging allows exact atomic positions to be
determined while spatially resolved, atomic resolution EELS
measurements give access to the elemental distribution at lattice
positions.
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SuperSTEM1:
Ripples in suspended Graphene
Spatial frequency filtered HAADF image to show ripples in suspended graphene. Black ‘beads’ are the centres of 'benzene' rings. The bead-strings gave a separation of 0.21 nm, the colour coding is chosen so that the atoms on tops and in throughsof ripples appear yellow and in the flanks bluish. The ripple amplitude is ~0.5 nm and their ‘wavelength’ ~5 nm
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SuperSTEM1:
Suspended Graphene with 'dislocation' dipole
Atomic structure of suspended mono-layer graphene, containing a separated ‘dislocation’ dipole, which consists of a shuffle (bottom) and a glide (top) segment. The model structure is overlaid. These dipoles have been predicted by theory. In contrast to semiconductors, where the shuffle segment in sessile and the glide segment is mobile, in graphene the shuffle segment is the mobile, ‘gliding’ segment; lattice resolution HAADF image, low-pass filtered
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SuperSTEM1:
Suspended Graphene
Atomic structure of suspended graphene, one mono-atomic layer of graphite (just like chicken wire-see ball and stick model), incorporating carbon ad-atoms on C-C bonds and a vacancy; lattice resolution HAADF, low-pass filtered
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SuperSTEM2:
SmartScan
Using a customized STEM EELS acquisition technique it is
possible to reduce beam damage by spreading the dose along a rapidly
scanned line during spectrum acquisition while keeping the atomic
resolution of the UltraSTEM along a line profile. (read more)
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SuperSTEM1:
(a) Aberration corrected HAADF High Resolution Scanning Transmission Electron Micrograph (HRSTEM) of a zinc-blende quantum well in a wurtzite segment.
b) An atomistic model of a wurzite/zinc-blende/wurtzite heterostructures along with a schemitcs of the band diagram. The Ga and As atoms have been marked in orange and green, respectively, for the WZ domains, and in red and blue, respectively for the double unit zinc-blende quantum well.
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SuperSTEM1:
Cellular Structure (stained)
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SuperSTEM2:
Human hepatic ferritin mineral core: Alignment and
classification of 750 particles. The tetrad view is still very clear,
but less common than in the entire image set. Scale bar is 10nm. Color
insert shows single particle 3D reconstruction. (Publication)
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SuperSTEM 1: Sum of seven aligned HAADF-STEM images of an intrinsic Si nanowire showing impurities trapped at a twin defect and bulk impurities. The unique optical sectioning properties of aberration corrected STEM was used to acquire HAADF images at various depths through a Si nanowire so that the 3D distribution of Au atoms could be determined for the first time. |
SuperSTEM 1:
Gold nanoparticles imaged at 80 kV (left). Small gold clusters on carbon appear less mobile (and thus sharper in the image) at low kV (right).
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SuperSTEM2:
Nanotoxicity: what is in the air you breath?
This image shows particles of magnesium oxide captured from the smoke
of burning magnesium metal. It was recorded at the SuperSTEM facility
at Daresbury Laboratory on an electron microscope that has compensation
for the defects in its lenses. It was collected on a digital camera, and
has been Fourier filtered to remove artefacts from the camera. The diameter
of the field of view is approximately 300nm.
The structure of these particles produced
in a simple plume of smoke are a reminder that there is a hidden world
beyond our everyday perception. In the past few decades our ability to
study and manipulate materials at the "nanometre" scale (a billion
times smaller than a metre) has immensely improved. Tailor-made particles
of this size are being produced for use in many applications including
medical diagnostics and treatments. However, methods to determine the
safety of such materials are only beginning to be developed. There is
a tremendous potential for such technology, but only if the risks are
rigorously assessed.
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website contact: dorothea@superstem.org |
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