Microscopy Group
Facilities: 4000EX


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The JEOL 4000EX is a 400kV dedicated high resolution TEM with a LaB6 source, which was installed in 1990.

This instrument has an objective lens polepiece designed specifically for optimum HREM performance. The top entry stage results in excellent sample stability over long periods.

Tilts of up to 25 can be achieved in a polepiece that has a very narrow gap and hence a low spherical aberration coefficient of 0.9 mm. This results in a high point-to-point resolution of 0.17nm (information limit 0.135nm).

The 4000-EX II is used almost exclusively for high resolution TEM, and as such is used to acquire focal/tilt series for the reconstruction of atomic structure.

Facilities available on this instrument include:

A six cartridge top-entry sample stage, in which specimens and holders can be kept under vacuum while not being analysed, minimising contamination problems

Three double tilt holders: one high tilt ( 25) and two standard ( 10)

Dual liquid nitrogen anti-contaminators for the specimen entry stage and the polepiece gap

A computer-controlled system for automatic microscope alignment and the acquisition of defocus/tilt series

A low light level TV camera

Use of this microscope is restricted to specifically trained individuals. Contact Jon Barnard (jsb43) for training.