652 Double Tilt Heating Holder™

High Temperature TEM

Many phenomena of both fundamental interest and commercial importance occur at elevated temperatures. The use of specimen heating holders greatly increases the usefulness of TEMs in microstructural studies and allows the direct observation of phase changes, such as nucleation and growth and dissolution processes.

The HotHinge™

The 652 includes the HotHinge™, a method for making miniature, fatigue resistant, heater wire connections to a tilting, high temperature furnace. When combined with three other Gatan innovations, the anti-drift tip, ToggleTilt™ system and the Hexring®, heating holders are produced that have exceptional performance, simplicity and reliability. Specimens can be heated to 1000°C in less than a minute using less than 8 watts of power.

Fast Temperature Response

The mass of the specimen furnace in both the single and double tilt holders has been made as small as possible to ensure rapid response to changes in heater current. The rate of increase of specimen temperature can be controlled as required, to a maximum of 4000°C per minute, or held at any selected temperature for long periods for the study of diffusion processes and precipitation kinetics.

High Resolution, Low Drift

Gatan heating holders have been designed to have minimum thermal drift. First, the mechanical link between the heater and the stage has been made with a material having near zero coefficient of expansion. Second, the specimen tip temperature has been held as closely as possible to the temperature of the specimen stage by water cooling of the specimen rod. Third, heat loss from the furnace to the specimen tip has been minimized by careful design of the ceramic furnace supports.

Resistance to Welding

The furnace is constructed of tantalum because of its high-temperature strength and resistance to solid state welding to most technical materials (including silicon). Tantalum anti-welding rings are provided to separate the specimen from the furnace so that if welding does occur the furnace will not be damaged.

Secure Specimen Clamping

Specimens are secured using the Gatan Hexring® system, assuring easy loading and good thermal contact between the specimen and the furnace.