925 Double Tilt Rotation

Ultimate Orientation Control in an Analytical Holder

Combining the tilting capability of our 646 double tilt analytical holder and the continuous rotation of the 650 single tilt rotation holder, the 925 allows the materials microscopist to simultaneously adjust tilt in two axes and rotation at any orientation of the specimen. Low vibration, minimum backlash and smooth operation are achieved with the titanium-geared cradle-drive mechanism. Precision gearing and jeweled bearings ensure smooth, continuous 360° rotation in both directions.

Analysis of Planar Features in Fragile Samples

Planar features within a TEM specimen are most easily studied if the specimen is first rotated until the planar feature is aligned parallel to the main tilt axis of the specimen holder. Manual removal of the specimen for reorientation can cause a fragile sample to break. With the 925 holder all orientation changes can be achieved once the sample has been clamped into the specimen cradle and inserted into the TEM. For EDX and EELS studies the boundary is oriented parallel to the electron beam in order to maximize the thickness of boundary material available for analysis and also to permit a more precise determination of the spatial extent of the segregation.

Larger Tilt Range

The Gatan 925 Double Tilt Rotation holder with +/- 60° alpha tilt, +/- 25° beta tilt and 360° continuous rotation has access to a much larger range of tilt angles than does a conventional double tilt holder or single tilt rotation holder. This feature can be very important when studying low-symmetry crystals over a wide range of orientations before a full crystallographic analysis can be performed.

Low Background Design

The beryllium specimen cup with Hexring® clamping system minimizes unwanted x-ray signal from the holder. Beryllium is chosen for its low fluorescent yield and for the low detection efficiency of its characteristic radiation. Other parts of the specimen holder tip that cannot be made from beryllium are made from high-strength titanium in a further attempt to minimize the x-ray signal from the holder and the surrounding microscope.

Hexring® Clamping System

Gatan developed the Hexring® system in 1980 to overcome the problems associated with spring clips and slotted threaded rings. The main advantages are the ease with which the clamping force on the specimen can be controlled and the ease with which the clamping ring can be loaded into the specimen cradle using the Hexring® tool. In all Gatan analytical holders, Hexrings® are made of beryllium.