Accepts either rod- or cone-shaped specimens and rotates them fully through 360º about the axis of the holder. Allows 360° image acquisition and tomographic reconstruction without the loss of information due to the missing wedge.

Single-axis tomography typically 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.

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 On-Axis Rotation Tomography Holder is removed from its loading station, the cartridge is mechanically interlocked into the holder.

Initially, the specimen can be fully rotated through 360° to select the proper specimen orientation. A stop is then engaged, which fixes the continuous rotation of the specimen with respect to the holder. A three-position precision indexing mechanism provides the means to orient the specimen in 120° increments. At each increment, while keeping the specimen position fixed with respect to the holder, the microscope’s goniometer is tilted to ±60° to acquire a tomographic tilt series. Indexing the rotation of the specimen by 120° two more times, combined with the ±60° goniometer tilt, yields data corresponding to 360° of specimen rotation. This procedure maximizes the amount of tomographic data obtained from a single specimen.

Included with the holder are a holder loading stand, a Model 9010 Vacuum Storage Container, a cartridge loading station, 1.8 mm and 1 mm cartridges, 1 mm sample posts (pack of 10), FIB stub assembly, and two types of tweezers (Dumont #3 and Dumont 2E1/8).

• Ideal for specimens prepared by a focused ion beam (FIB) tool
• Ideal for atom probe tomography (APT) and field ion microscopy (FIM) specimens
• Three-position index allows precise axial rotation of the specimen
• Compatible with all pole-piece gap geometries
• Is compatible with the microscope’s touch alarm, which stops goniometer movement in the event that a pole touch occurs

Available for both JEOL and Thermo Fisher Scientific microscopes.