Centers - Electron Microscopy Unit

The Tecnai 12 TWIN TEM (FEI) is an instrument With a state of the art design combining high contrast and resolution essential to visualizing image details in a wide range of samples at both room and liquid nitrogen temperatures.

This microscope enables studies in a broad

spectrum of science from hard to soft matter. From one hand, the high tilt capabilities of this microscope, equipped with single and double tilt holders, allows to perform high quality study of crystalline materials; from another hand, the set up in our laboratory, including a Low-Dose exposure technique, is configured to be optimal for cryogenic transmission electron microscopy (cryo-TEM). This TEM is equipped with a fully computerized goniometer (with ±60 degrees of eucentric tilt), and two MultiScan CCD cameras (Gatan 791 wide angle and Gatan 794) allowing to record images of high quality.

EM unit provides a training course (hands-on) on operating the microscope (see syllabus).

Specifications (as given by FEI):

Electron Source

· W or LaB6 emitter

· High voltage range 20 – 120 kV or continuously variable

· High stability and long life time of filament

Illumination system

· Four-lens illumination lens

· User-selectable intensity limit for specimen protection

· User-selectable zoom for constant screen intensity

Imaging

· Five-lens magnification system

· High contrast (TWIN lens)

· Automatic contrast enhancement function

· Focusing aid, adjustable wobbler for all magnifications and directions

· Focus preset for focusing at eccentric position

· Rotation-free magnification and diffraction series

· Magnification reproducible within 1.5 %

· Embedded 2 CCD cameras

Specimen stage

· Fully computer-controlled, eccentric side-entry, high-stability CompuStage

· Maximized tilts for any X, Y, Z, a combination

· Choice of a variety of specimen holders: cryo, double and single tilt

· X, Y movement 2 mm, specimen size 3 mm

· For specimen recall accuracy <= 0.1 µm (X, Y) and <= 0.1 º (a) attainable

· Maximum drift < 1 nm/minute with a standard holder

· High tilt (±60°) and large field of view

Vacuum

· Fully interlocked differentially pumped column.

· Ultra-high vacuum for contamination-free observation

· Cryo shields with a 3 mm hole

· Vacuum levels of specimen chamber and gun area < 2.7 x 10-5 Pa

Optics

Scanning Electron Microscope – JSM-7400F

The JSM-7400F (JEOL) ultrahigh resolution cold FEG-SEM is one of the most advanced instruments available in the world for imaging semiconducting and insulating materials such as polymers and ceramics without the need for coating the samples with a conducting film as in conventional SEM.

This UHR-SEM was custom designed with six

different detectors, including conventional and in-lens SE and BSE detectors,

cathodoluminescence mapping and a customized Noran Vantage EDS detector for elemental analysis of elements down to Boron. EM unit provides a training course (hands-on) on operating the microscope (see syllabus).

SEM Manufacturer Specification (JEOL)

EDS Specification (Thermo Scientific):

Liquid-nitrogen cooled x-ray detector.

Crystal Area – 10mm2

Crystal Type – Si(Li)

Energy Resolution – 129 eV

Window – single Norvar

Vitrobot (FEI)

A fully automated vitrification device for plunge-freezing of liquid suspensions.

Operating parameters

Working Temperature

4 - 70° C (at an ambient temperature range between 18 - 25° C)
Peltier controlled heating/cooling

Relative Humidity Ambient humidity - 100 % (no condensation at an

RH < 85%)
Ultrasonic controlled humidification Instrument Control

• The Vitrobot™ is fully controlled by an embedded/integrated PC using Windows as the main operating system.

• Specific instrument control and operational parameters set-up are done through a mouse controlled User Interface and/or with a mechanical foot-pedal switch. Sample Application

• Software controlled dipping/withdrawing of the grid from a vial. Small sample

volumes can also be applied manually through a small side port allowing access to a pipette.

• Both application time and wait time (time between application and blotting) are software controlled and can be set in the User Interface Blotting Device

• Access of fluids is removed from the grid by (repeatedly) blotting with filter paper on rotating foam pads.

• Number of blotting actions (max. 16 times for one grid) and the duration of blotting (blot time) is software controlled and can be set in the User Inteface.

• Longitudinal grid positioning ('blot offset') as well as the wait time between blotting and vitrification ('drain time') is user definable.

Vitrification Process

• Automated shutter control allows for an instant and smooth injection of the

sample grid into the container with liquid ethane/propane. A lift for the container brings the coolant as close as possible to the shutter to ensure optimal

vitrification.

• Parallel coupling between lowering of the coolant container and position of the frozen grid remaining inside the coolant. This minimizes any possible contamination prior to the sample transfer into a storage box or cryo holder

Sputter Coater – Emitech K575X

The Emitech K-575X is a versatile sputter coater for coating samples for ultra high-resolution SEM. It is currently equipped with Cr, Pt, Au and Carbon targets for producing coatings that are in the order of few angstroms in thickness. This unit utilizes a turbo molecular pump which is backed up by a rotary pump. The chamber size is 165mm in diameter x 125mm in height. The instrument is equipped with a K250 Carbon Coating attachment and a K350 Sputter/Glow discharge attachment.

FEATURES:

• Fully Automated Control

• Ultra High Resolution

• Thin Film Deposition

• Turbo Molecular Pumping System

• Modular Control Electronics

• Clean Line Design

Update Date: 17/05/2010