Examples of LEO 1455 VP SEM applications

The LEO 1455 VP is a highly versatile scanning electron microscope that can be used for both imaging and analysis of specimens.

Secondary electron and backscattered electron images of a fossil foram
Secondary electron and backscattered electron images of a fossil foram

This example highlights the benefits of imaging in variable pressure secondary electron mode.

Elemental differences in the mountant resulted in traces of gum masking some of the type specimen’s surface ornamentation in the backscattered electron (BSE) image. In comparison, the secondary electron (SE) image shows a high level of detail and good contrast.

Low and high vacuum mode secondary electron images of an impact crater on the Hubble Space Telescope
Low and high vacuum mode secondary electron images of an impact crater on the Hubble Space Telescope

Some materials, such as type specimens, cannot be coated with a conductive layer (usually carbon or gold). Imaging therefore needs to be carried out in low vacuum mode (Low-vac) to avoid charging effects - as seen in this high vacuum mode (Hi-vac) secondary electron image of an impact crater in a solar cell on the Hubble telescope.

Backscattered electron image of a section of the Vigarano carbonaceous chondrite meteorite
Backscattered electron image of a thick section of the Vigarano meterorite

This carbonaceous chondrite meteorite section was imaged using the Oxford Instruments INCA automated montaging software. Compare the energy dispersive X-ray (EDX) phase map of the same section in the next slide.

An energy dispersive X-ray (EDX) phase map of a section of the Vigrano meteorite
Energy dispersive X-ray (EDX) phase map of a thick section of the Vigrano meteorite

Red = magnesium, blue = aluminium, green = calcium.

Like the corresponding backscattered electron image in the previous slide, this EDX phase map of the meteorite section was produced using the Oxford Instruments INCA automated montaging software.

Scanning electron microscope image of galena crystals
Galena crystals

These tiny crystals of the mineral galena - lead sulphide - have been made in the laboratory under carefully controlled conditions. The crystals grow in about two weeks to a maximum size of approximately 0.5mm.

The crystals are grown suspended in a gel, rather than on a solid surface, to ensure they develop their characteristic forms equally in all directions. Cubes, octahedra and interpenetrating twins can all be seen, as well as spiral growth structures on the crystal surfaces.  

The purity of the crystals can also be controlled, making them suitable for geochemical experiments.

The image has been artificially coloured by computer.

Close-up of a false-coloured scanning electron microscope image of a section of butterfly wing
Close-up of a section of butterfly wing

Butterfly wings are covered in thousands of delicate scales which are easily brushed off. They improve the aerodynamics and help in temperature regulation in much the same way as feathers do for birds. They also produce the coloured patterns on wings. 

Some colours are produced by simple pigmentation, while others - the iridescent colours seen on many tropical butterflies - are a result of scales' three-dimensional structure. The structure of each scale reflects light at different wavelengths. These interfere with each other and cause the colour of the scale to change depending on the viewing angle.

The image has been artificially coloured by computer.