Gatan, Inc.

Peter R Swann

Joseph S Jones

Bernd Kraus

An ultra-high tilt cryotransfer holder is provided which is capable of rotating a specimen through a full 360.degree. tilt angle (180.degree. from horizontal in both clockwise and counterclockwise directions) without spillage of cryogenic liquid, and while maintaining proper protection and cooling of the specimen. The cryotransfer holder includes a holder body having a specimen tip and a source of cooling for the specimen tip. The specimen tip includes a specimen grid of a thermally conductive material which has a plurality of grid openings between crossing grid bars. The grid may be extended from the holder into a forward viewing position or retracted into a protected position within a cryoshield.

Ultra-high tilt specimen cryotransfer holder for electron microscope

An ion beam milling system for the preparation of transmission electron microscope specimens suitable for atomic resolution imaging, particularly of III-V and II-VI compound semiconductors and their alloys, is described. The system includes ion beam sources and reactive molecular gas jets which may be operated in combination or separately, as appropriate. A new heated specimen holder, giving greatly increased reaction rates with the molecular gas jet, allows milling angles very close to zero.

Chemically-assisted ion beam milling system for the preparation of

A specimen heating holder for side entry transmission electron microscopes is described. The holder permits specimen tilt about two orthogonal axes and has the capability of raising the specimen temperature to .about.1000.degree. C. A novel hinged electrical connection, resistant to fatigue, supplies, supplies power to a heater within the specimen cradle. Special low thermal conductivity cradle bearings minimize the required heater current and promote ease of assembly yet are sufficiently strong to make specimen loading easy.

Specimen heating holder for electron microscopes

An improved specimen cooling holder for transmission electron microscopy is described. Low thermal conductivity pins near the specimen and an improved conductor/dewar connection reduce specimen vibration, providing improved image resolution. Multiple heaters facilitate accurate temperature control and bakeout procedures.

Specimen cooling holder for side entry transmission electron microscopes

An improved electron microscope anticontaminator having a conduction rod enclosed within an independent vacuum system and micropositioning capability is described. The micropositioning facility allows the use of unusually small apertures in the cold anticontaminator block with a consequent improvement in efficiency of function. A self-contained contact sensor provides immediate audible warning of contact between a specimen holder and the cold anticontaminator block, permitting the removal of the usual mechanical end-stops for the specimen tilt mechanism and allowing the maximum specimen movement possible at any time. The independent vacuum system in combination with a heater positioned close to the anitcontaminator block allows the microscopist to vent the microscope column without removing the anticontaminator from the microscope. Special anticontaminator blocks incorporating multiple apertures or an X-ray collimator eliminate the need for separate microscope objective aperture or X-ray collimator mechanisms and also ease design constraints imposed by the very limited space around specimens in high resolution microscopes.

Anticontaminator for transmission electron microscopes

An electron microscope cryotransfer holder capable of simultaneously transferring several specimens is described. A cryo-shield protects the specimens from warming or frosting during the transfer from the specimen-loading workstation into the microscope.

Multiple specimen cryotransfer holder for electron microscopes

A device comprising a television camera mounted inside the projection chamber of a transmission electron microscope with the imaging surface perpendicular to the optical axis of the microscope. The electron image is converted to a light image by high efficiency YAG transmission scintillator and transferred by a low loss fiber optic plate to a CCD imaging device. The camera is moved by a pneumatic piston between the operating position where it intercepts the electron beam and a position where the electron beam can pass unobstructed to the main microscope viewing screen.

TV system for transmission electron microscopes

A device interposed between an electron microscope specimen holder and a microscope translation stage constructed of a special combination of materials arranged in such a manner that little or no specimen drift occurs when the temperature of the complete assembly is changed. In the first and more common arrangement, the device is placed in the nose of the standard microscope specimen holder and consists of a silica rod inside a metal tube, the material of the tube having a larger coefficient of thermal expansion than the material of the specimen rod. In the second, and less common arrangement the device is placed on the opposite side of the specimen away from the nose of the holder and consists of one tube, the material of which must have a larger coefficient of thermal expansion than the material of the specimen holder.

Anti-drift device for side entry electron microscope specimen holders

An ion milling machine specimen elevator comprising a vertically oriented piston which supports a specimen holder at its top and is movable between a lowered operating position and a raised viewing position. When the piston is in the lowered operating position, it is slowly rotated about its vertical axis by a suitable drive. The elongated piston passes through an O-ring seal into an evacuated ion milling or work chamber. At the bottom of the work chamber is disposed a pneumatic control cylinder into which the piston extends. The piston can be moved up or down by altering the pressure in the pneumatic cylinder. During ion milling the piston is at its lowest position in the evacuated work chamber and is held there by pressurized gas in the pneumatic control cylinder. A second small chamber is provided above the work chamber for specimen viewing and specimen exchange. The disclosed specimen elevator can move the specimen into the second chamber and at the same time provide a seal so the work chamber does not lose vacuum during specimen viewing or exchange. If it is desired to remove the specimen from the work chamber without disturbing its vacuum, the pressure in the pneumatic control cylinder is released and the elongated piston is automatically forced to its highest position by the exerted atmospheric pressure. As the elongated piston rises to its upper position the top of the piston passes through a second O-ring seal, at the top of the work chamber, then into the small second chamber. As the piston moves into the small second chamber, it seals the work chamber from the small second chamber so air admitted to the second chamber does not enter the work chamber. The small chamber can be lifted from the larger work chamber after the internal pressure of the small chamber is raised to atmospheric. Removing the small chamber exposes the specimen holder, allowing the specimen to be removed or closely examined to study the progress of the ion milling operation. The specimen is reinserted into the work chamber by replacing and then evacuating the small chamber and then by repressurizing the pneumatic control cylinder. This forces the piston to move through the seal between the work chamber and the small chamber to its lowest position. The piston has a beveled gear attached thereto which engages a driven bevel gear when the piston is in the lowered operating position to slowly rotate the specimen in the work chamber.

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Diablo, CA, United States of America

Peter R Swann