Hitachi S4700 Field Emission Microscope

What the heck is a Scanning Electron MicroscopeIt is a microscope that uses electrons to provide a light source for the magnification of objects.

Why does it look different than a regular microscopeElectrons 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.

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.

Different guns are similar to different watt light bulbs, less wattage less light and lower resolution.

Are there different types of Electron GunsIncreasing BrightnessTungsten FilamentLaB6 Single CrystalField Emission Tungsten Single Crystal

So What Do Scanning Electron Microscopes Look AtScanning 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 MicroscopeIt 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-200,000xSamples include:

Thin filmsCeramicsMetalsBiologicalCompositesPolymers76.6m

Thin FilmsEpitaxial Thin films on gold single crystalPhoto resist in vias in a silicon wafer

CeramicsCarbon NanotubesHigh Temperature Ceramics, Titanium Diboride

MetalsPhase contrast on heat treated PtFracture surface after tensile testing

CompositesPolymer added to glass for strengthGlass bead chemically altered to hydroxy apatite, bone material

PolymersPolyurea aerogelTitanium dioxide particles in epoxy for added strength

Elemental MicroanalysisAl Cu

Ca PbThe Hitachi S4700 is equipped with an Energy Dispersive Spectrometer for elemental microanalysis determinations.

Interesting Crystal Shapes