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Hitachi S4700 Field Emission Microscope. What the heck is a “Scanning Electron” Microscope. It is a microscope that uses electrons to provide a light source for the magnification of objects. Why does it look different than a “regular” microscope.
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What the heck is a “Scanning Electron” Microscope It is a microscope that uses electrons to provide a light source for the magnification of objects.
Why does it look different than a “regular” microscope Electrons are very small and need a vacuum to work properly. If an electron hits an atom of anything it will loose direction and not be available to “illuminate“ the object.
How Does a Scanning Electron Microscope work Electrons are produced by a “gun” or source They are accelerated down the column that is under vacuum Then focused by magnetic lenses The beam of electrons are then moved across the object by the scanning coils. As the electrons move across the object they cause electrons to eject from the specimen These new electrons are detected and reconstructed to produce an image on a screen.
Are there different types of Electron “Guns” Tungsten Filament Increasing Brightness Different “guns” are similar to different watt light bulbs, less wattage less light and lower resolution. LaB6 Single Crystal Field Emission Tungsten Single Crystal
So What Do Scanning Electron Microscopes Look At Scanning Electron Microscopes allow us to see things that are very small http://www.eoearth.org/article/Nanoparticles
The Hitachi S4700 is a Field Emission Scanning Electron Microscope It has a resolution of 2.3 nm, about 0.00003 the size of a human hair. Magnification range is 250x-500,000x. Typical magnifications used 250x-200,000x Samples include: • Thin films • Ceramics • Metals • Biological • Composites • Polymers 76.6m
Thin Films Epitaxial Thin films on gold single crystal Photo resist in vias in a silicon wafer
Ceramics Carbon Nanotubes High Temperature Ceramics, Titanium Diboride
Metals Fracture surface after tensile testing Phase contrast on heat treated Pt
Composites Polymer added to glass for strength Glass bead chemically altered to hydroxy apatite, bone material
Polymers Titanium dioxide particles in epoxy for added strength Polyurea aerogel
Elemental Microanalysis The Hitachi S4700 is equipped with an Energy Dispersive Spectrometer for elemental microanalysis determinations. Al Cu Ca Pb