Environmental scanning electron microscope Philips XL30 ESEM FEG
The environmental scanning electron microscope Philips XL30 ESEM FEG employs a Schottky based gun design using a point-source cathode of tungsten, which has a surface layer of zirconia (ZrO2). The working temperature of the emitter is 1800°K, the tip is always kept clean, flashing is never needed, it takes only a minute to become fully operational for a long period. The brighter electron source possesses both low energy spread and low current fluctuations, resulting in higher effective currents in smaller probes. Particularly for low beam energies, the high spatial resolution is the answer for modern materials microscopical investigation.
This instrument has the performance of a conventional SEM but has the advantage that practically any material can be examined in its natural state in a gaseous environment at pressures as high as 1330 Pa (10 torr)) and at temperatures as high as 1500°C. Due to the multiple pressure limiting apertures (PLA) and its environmental secondary electron detectors (GSED), the microscope can offer high-resolution images in a saturated water vapour environment keeping the sample in its original wet state (minimum 4.6 Torr at 0°C).
Dehydration and hydration in the ESEM is a question of temperature and vacuum pressure: a Peltier cooled specimen stage offers the possibility to maintain water on the samples inside and to investigate samples between -5 and +60°C. The stage is mounted on the ESEM four-axes motorized stage (x,y,z and rotation) using the stage adapter and is controlled to provide accurate and stable automatic temperature control. The need of sample preparation is eliminated (particularly conductive coatings) and allowing the possibility of investigation of dynamic processes.
A 1000 and a 1500°C heating stage can be mounted on the ESEM universal stage adapter. The heating modules are cooled (water chiller) and controlled by a high temperature measurement and control system. The samples are heated from the sides to obtain a more uniform temperature around the sample. To lead the electrons towards the high temperature detector (ESD), the sample bias (crucible) and the bias on the steel disk of the high temperature heat shield assembly can be changed.
A Deben MicroTest tensile test system with a 200N tensile module and 4-Point bending clamps make it possible to study the microstructure of materials during the deformation process. The module is motorised and is software controlled in a Windows environment, which displays all system parameters and the stress strain curve. With an FEI micromanipulator / micro-injector for XL30 installed on the specimen chamber the sample can be physically contacted with a small probe or various fluids can be added to the sample. The manipulator can be moved in three directions: x, y and z. The dynamic processes can be recorded with a Philips video recorder VR330.
A hydrocarbon-free turbo pumped independent CryoSEM system Emitech K1250 can be interfaced to the microscope. The specimen preparation can be performed separated from the microscope in a preparation unit, which consist of a freezing chamber and a preparation chamber (fracturing and coating). The heaters, one for the preparation chamber and one for the SEM cold stage give accurate temperature and timing control.
The microscope is equipped with an EDAX energy dispersive x-ray detector with an ultra thin window. The EDAX software allows qualitative and standardless quantitative analysis from Boron onwards. Software for automated point analysis, linescans and spectral mapping is available. The ESEM can acquire x-ray data from insulating materials at high accelerating voltages. The EDX-system allows to acquire analytical information in high vacuum and ESEM mode, because of a solid-state backscattered electron detector (BSE) and gaseous analytical detector (GAD) with cone as well as standard and high-pressure secondary detectors (ESD) for ESEM mode. In order to attain the optimal settings for both SEM and analytical work, the microscope is equipped with a multiple objective lens aperture. An Electron Flight Simulator software version 3.1 has been installed. A CCD camera is mounted to allow the user to monitor the position of the sample inside the specimen chamber.
The SEM and the EDAX system operate within a Microsoft Windows environment. Using a mouse and keyboard all given commands conform the application software are translated into action. Intermediate functions include rotation-free focussing, constant spot size, auto focus, auto stigmator, on screen X and Y measurements, automatic contrast and brightness, power zoom, image manipulation, graphics editor. A multi-user shell software allows logging the actions of all individual users.
Data and images can be stored on the hard disc of a network computer. Printing with a HP Deskjet 960c and with a Sony videoprinter offers the users the necessary output possibilities.
|Resolution:||2.0 nm at 30 kV; 2.0 nm at 30 kV and 10 mbar H20 vapour.|
|High tension:||continuously variable from 0.2 till 30 kV.|
X & Y: 50 mm.
Z: 50 mm total.
Rotation: n x 360°.
Tilt: at FWD 10mm, -15° to +75°.
Max. free space (min. WD): 3mm in high vacuum, 5 mm in wet mode
|Multiple differential vacuuum system:||
specimen chamber, ODP and two pre-vacuum RP: 1 x E-4 Pa (1 mbar)
in high vacuum mode and 10 to 1330 Pa with H2 vapour or
intermediate vacuum, IGP: 1 x E-5 Pa (1 x E-7 mbar ).
gun vacuum, IGP: 5 x E-7 Pa (1 x E-9 mbar).
standard image (702 x 484 pixels - 341 KB )
high definition image ( 1404 x 968 pixels - 1.31 MB)
|Backscattered electron detector:||better than 0,1 Z at Z = 30|
Super Ultra Thin Window - detection from Boron - resolution: 130eV F.W.H.M by MnKα for 50 µsec amplifier time constant - Phoenix - software version 3.3: spectral analysis and linescan.
-scientific: Ludo Froyen tel 016/32.12.77
-technical: Rudy De Vos tel 016/32.12.73
Room: 00.07 f no phone