Cooling Holders

Applications

TEM specimen cooling holders are mainly used to reduce contaimination due to carbon migration and to observe low-temperature in situ phase transformations. The holders may also be used to reduce unwanted thermal effects in cathodoluminescence and convergent-beam electron-diffraction experiments and to facilitate EDX and EELS analyses by reducing contamination and mass loss.

Low Drift and High Resolution

Gatan cooling holders achieve their high mechanical stability by conduction cooling from well-insulated, bubble-free dewars. Resolution is limited mainly by thermal drift in the microscope specimen stage. Drift in the specimen holders has been almost entirely eliminated by a spring loaded, sliding silica rod mounted in the specimen tip.

Precise Temperature Control

The specimen holder tip temperature is monitored by a calibrated silicon diode. This type of sensor has the following advantages over a thermocouple:
• Output is not affected by cold-junction temperature gradients
• More sensitive
• More linear temperature response.
The conductor rod connecting the specimen holder tip to the nitrogen dewar contains an electric heater to control the specimen temperature.

Hexring® Clamping System

The Gatan Hexring® specimen-clamping system guarantees good thermal contact with the specimen. Gatan cooling holders are designed so that the whole specimen holder tip is cooled and not just the specimen cradle. This ensures the minimum possible temperature gradient around the specimen. Gatan developed the Hexring to facilitate easy sample loading without the difficulties associated with spring clips and slotted threaded rings. This system uses a clamping mechanism that can be easily manipulated and ensures easy specimen clamping control. The Hexring and washers are made of beryllium for analytical applications and tantalum or Inconel for use in heating holders.

Available Cooling Holders from Gatan:

Please note: Tilt ranges of specimen holders vary according to the manufacturer, model, polepiece, and the presence of in-gap accessories of the TEM used. When ordering, please specify the TEM make, model, polepiece, configuration of the EDX detector (if any), and local voltage requirements.

Gatan manufactures a wide variety of analytical, cooling, heating, straining, and other specialty or custom holders for most microscope makes and models. Contact your local Gatan representative for more information about specific holders and microscope configurations.