On-Axis Rotation Tomography Holder – Model 2050
Accepts either rod- or cone-shaped specimens and rotates them fully through 360° about the axis of the holder.
- Ideal for specimens prepared by focused ion beam (FIB)
- Ideal for atom probe tomography (APT) and field ion microscopy (FIM) specimens
- Allows 360° image acquisition and tomographic reconstruction without the loss of information due to the missing wedge
- Three-position index allows precise axial rotation of the specimen
- Compatible with all pole-piece gap geometries
Fischione recommends that you clean the specimen and specimen holder with the Fischione Model 1020 Plasma Cleaner or Model 1070 NanoClean before insertion into the TEM.
During collection of tomographic data, the electron beam will be on the same area of the specimen for an extended time. As a result, organic contamination may build up on the specimen. A plasma cleaning time of 10 seconds to 2 minutes removes the contamination. Longer cleaning times can remove contamination spots caused by previous TEM viewing of non-plasma cleaned specimens.
When not in use, the holders should be stored under vacuum in Fischione Model 9010 Vacuum Storage Containers or the Model 9020 Vacuum Pumping Station.
Highly innovative holder for rod or cone specimens
The highly innovative Model 2050 On-Axis Rotation Tomography Holder accepts either rod- or cone-shaped specimens and rotates them fully through 360° about the axis of the holder.
The preparation of rod or conical specimens is an extension of conventional TEM methodology which has historically been associated with a 3 mm diameter disk specimen. With the advent of electron tomography, combined with advances in specimen preparation technology, it became necessary to develop a specimen geometry and holder to optimize three-dimensional tomographic information from the specimen.
On-axis rotation – no information loss
Traditionally, single axis tomography results in
a missing wedge of information and dual-axis tomography results in a missing pyramid of information. On-axis rotation tomography yields results without the loss of any information, thus providing the maximum achievable amount of data from the specimen.
The On-Axis Rotation Tomography Holder features a cylindrical specimen cartridge into which a specimen post is inserted. Specimen posts are available in a diameter of either 1.8 mm to accept common atom probe field ion microscope (APFIM) specimen mounts or 1 mm to accept focused ion beam- (FIB) prepared specimens.
In the case of FIB, lift-out techniques are used to transport and attach a thick specimen to the tip of the specimen post. Then the specimen is further FIB-milled into a rod or cone shape and to electron transparency. The specimen post is clamped into the specimen cartridge. The specimen cartridge precisely fits within the body of the holder and is accurately aligned with the eucentric plane of the microscope. The cartridge is rigidly affixed to a mechanism that both moves along and rotates about the axis of the holder.
A dedicated loading station facilitates the positioning of the cartridge into the holder. Once the specimen cartridge has been loaded into
the holder, longitudinal movement is manually activated to retract the loaded cartridge into the body of the holder. This protects the specimen during holder insertion in to and removal
from the TEM goniometer. Once the On-Axis Rotation Tomography Holder is removed from its loading station, the cartridge is mechanically interlocked into the holder so that it cannot become separated while the holder is in the microscope.
|Holder type||Room-temperature, single tilt
For most transmission electron microscopes (TEMs)
|Specimen size||1.8 mm cartridge
– Rod- or cone-shaped with electron transparent tip
– Base diameter up to 1 mm
– Length up to 20 mm 1.0 mm cartridge
Rod- or cone-shaped specimen is affixed to the tip of the specimen post
|Resolution||0.34 nm (in all directions)|
|Drift||< 1.5 nm/min|
|Maximum tilt range||Full 360° rotation, as well as indexing in three 120° increments|
All specifications depend on the microscope model, pole piece type, and aperture position.
For ultimate resolution and drift performance, the TEM must meet the manufacturer’s specifications.