Esteem
25/09/2017 - 01:03
(c)
http://esteem.ua.ac.be/main.aspx?c=TA5&n=1165
Activity Leader

Dr. Paul Midgley
Reader in Electron Microscopy
Department of Materials Science and Metallurgy
University of Cambridge
Pembroke Street
GB-CB2 3QZ CAMBRIDGE
UNITED KINGDOM
Phone + 44 1223 334 561
Fax     + 44 1223 334 563
E-mail: pam33@cam.ac.uk  
Website: www.cam.ac.uk


TA5

The EMCAM laboratory of the University of Cambridge has 8 transmission electron microscopes and 5 scanning electron microscopes, a wide range of sample preparation equipment and a large number of computer workstations and dedicated microscopy software.
The laboratory is specialized in three dimensional imaging of nanomaterials (electron tomography) and imaging or mapping of electronic or magnetic nano fields. At Daresbury a superstem will be installed (2005). The instrument will have a spatial resolution of 0.1 nm and an energy resolution of 0.3 nm.
EMCAM offers access to the following microscopes: a FEI Tecnai F20 FEG, a Philips CM300 FEG, SuperSTEM, a VG HB501 STEM, a Jeol 4000 EX, a Philips CM30 and a Jeol 2000FX.

 

 

Philips CM300 FEGTEM

 

 

The Philips CM300 is a state-of-the-art 300kV field emission gun (FEG) high resolution and analytical TEM/STEM, which was installed in 1999.

The field emission source means this microscope is ideal for applications requiring high coherency, high brightness at high magnification, or small focused probes.

Applications that require high coherency include electron holography and Fresnel defocus imaging, while high brightness applications include energy filtered microscopy, and focused probes are ideal for EDX, EELS and all STEM work.

The microscope has a SuperTwin objective lens with a maximum sample tilt range of ±60° (using a tomography holder) and a Cs of 1.2 mm. It has a point resolution of 0.2 nm and an information limit of 0.12 nm. The minimum focused probe size is 0.3 nm.


Facilities available on this instrument include:

 

Single tilt tomography, single tilt electrical, double tilt liquid nitrogen and double tilt low background sample holders

Three fold objective and condenser stigmators.

A Gatan Imaging Filter (GIF) 2002, fitted with a 2k x 2k CCD camera, for energy-filtered diffraction, imaging and EELS.

Off-axis STEM bright-field (BF) and dark-field (DF) detectors

On-axis high sensitivity (single electron detection) Fischione Model 3000 high angle annular dark field (HAADF) detector for high-resolution Z-contrast imaging

EMISPEC data acquisition system running ESVison for recording any combination of CCD, EELS, X-ray, BF, ADF and HAADF signals

An EDAX r-TEM ultra-thin window (UTW) X-ray detector

A Lorentz lens for high-resolution magnetic imaging

An electrostatic biprism for off-axis electron holography

A Balzers Prisma mass spectrometer connected to the objective polepiece for diagnosis of vacuum problems and analysis of specimen damage mechanisms 
 

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FEI Tecnai F20-G2 FEGTEM

 

 

The FEI Tecnai F20 is 200kV field emission gun (FEG) high resolution and analytical TEM/STEM, which was installed in June 2002.

Like the CM300, the microscope has a SuperTwin objective lens with a Cs of 1.2 mm. It is different from the CM300 in that it lacks a Lorentz lens for field free imaging and an electron biprism for holography. However, the ultimate STEM resolution is superior due to improved scanning coils.

The control system of the Tecnai is also very different to traditional microscopes, and a computer is the main control and analysis interface. This allows controls to be customised between users and digital acquisition to be integrated seamlessly.


Facilities available on this instrument include:

 

Ultra high tilt tomography (±80º), single tilt electrical, single tilt and double tilt low background sample holders

A Gatan Imaging Filter (GIF) 200, fitted with a 1k x 1k CCD camera, for energy-filtered diffraction, imaging and EELS

Off-axis STEM bright-field (BF) and dark-field (DF) detectors

On-axis high sensitivity (single electron detection) Fischione Model 3000 high angle annular dark field (HAADF) detector for high-resolution Z-contrast imaging

An EDAX r-TEM ultra-thin window (UTW) X-ray detector

 

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JEOL 4000EX-II TEM

 


The JEOL 4000EX is a 400kV dedicated high resolution TEM with a LaB6 source, which was installed in 1990.

This instrument has an objective lens polepiece designed specifically for optimum HREM performance. The top entry stage results in excellent sample stability over long periods.

Tilts of up to ± 25° can be achieved in a polepiece that has a very narrow gap and hence a low spherical aberration coefficient of 0.9 mm. This results in a high point-to-point resolution of 0.17nm (information limit 0.135nm).

The 4000-EX II is used almost exclusively for high resolution TEM, and as such is used to acquire focal/tilt series for the reconstruction of atomic structure.

 

Facilities available on this instrument include:

 

A six cartridge top-entry sample stage, in which specimens and holders can be kept under vacuum while not being analysed, minimising contamination problems

Three double tilt holders: one high tilt (± 25°) and two standard (± 10°)

Dual liquid nitrogen anti-contaminators for the specimen entry stage and the polepiece gap

A computer-controlled system for automatic microscope alignment and the acquisition of defocus/tilt series

A low light level TV camera

 

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Philips CM30 TEM

 

 

The Philips CM30 is a 300kV analytical TEM/STEM with a LaB6 source, which was installed in 1992.

The CM30 is a medium resolution instrument for bright field/dark field imaging, basic analytical microscopy and diffraction studies.

The STEM system allows point analysis by EDX and EELS, as well as spatially resolved EDX maps with a resolution of up to 3nm.

Much of the design and layout is similar to that of the CM300, so the CM30 is an ideal machine for preparatory training for users wanting to use the FEGTEM.

 

Facilities available on this instrument include:

 

Liquid nitrogen, low background double tilt and high-tilt tomography sample holders

A Gatan model 601 parallel electron energy loss spectrometer (PEELS) with EL/P software

An ultra-thin window (UTW) X-ray detector controlled by a Link Analytical AN2000 computer for digital acquisition of STEM images, EDX spectra and EDX mapping

A photo-multiplier STEM bright-field (BF) detector, solid-state dark-field (DF) and back-scattered electron (BSE) detectors

A low light level TV camera

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JEOL 200CX TEM


 

The JEOL 200CX is a 200kV analytical TEM/STEM with a W source, which was installed in 1996.


Facilities available on this instrument include:

 

A modified liquid nitrogen holder for EBIC studies

 

CAM5.jpg

 

 

JEOL 2000FX TEM

 

 

The JEOL 2000FX is a 200kV analytical TEM/STEM with a LaB6 source, which was installed in 1988.


Facilities available on this instrument include:

 

Liquid nitrogen, helium holders and low background double tilt sample holders

Parallel energy loss spectrometry (PEELS)

An ultra-thin window (UTW) X-ray detector

Secondary electron (SE) and back-scattered electron (BSE) detectors

 

CAM6.jpg

 

 

VG HB501 STEM

 

The VG HB501 STEM is a 100kV dedicated UHV field emission STEM, which was installed in 1990.

The cold field emission (CFE) gun is a very high brightness source, typically 10x brighter than a thermally assisted FEG (such as that on the CM300). This allows the formation of small probes (~1nm) with a very high current (~1nA), making the STEM ideal for EDX mapping.

The STEM is also ideally suited for EELS fine structure analysis, as the CFE gun has a very high temporal coherence with a nominal energy spread of ~0.4 eV.

This instrument is the only dedicated STEM in Europe to be fitted with a Gatan Imaging Filter (GIF). This allows the acquisition of angular and momentum dispersed EELS spectra, as well as the formation of energy-filtered diffraction and STEM images.


Facilities available on this instrument include:

 

A UHV-compatible 1k x 1k GIF for angle-resolved PEELS and energy-filtered diffraction

A second diffusion pump connected to specimen loading chamber for rapid specimen entry

A windowless Si (Li) X-ray detector with Link Analytical computer for digital acquisition and EDX mapping

BF, secondary electron (SE), HAADF and energy filtered STEM detectors.

A Digiscan system with Digital Micrograph control software for full digital acquisition of STEM images and EELS spectra

 

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