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www.leem-user.com
is hosted by the University of
Duisburg-Essen

 
 




Have you ever wondered...
What this piece might be good for? Or have you ever asked yourself "why can I get a decent image at this energy, but not at others?".
Here you might find the answer, and if the answer for your particular question is not yet available, you can simply contact us. If you are lucky, one of the LEEM experts in the world has the answer you are looking for.




General Questions

What exactly do you mean with "Mirror Mode"
How can I make sure to hit the sample surface perpendicular with the incident beam?


Website and Community

How can I become Part of the LEEM-User community?
Who is Running this Webpage anyway?


General
What exactly do you mean with "Mirror Mode?"

 
If you keep reducing the energy of the electrons before they hit the surface, at some point the energy will be so low, that the electrons don't reach the surface any more, but turn around in front of the surface. This is not useful for imaging, since you will just have a reflected electron beam. If you carefully adjust the voltage, though, then you can reach a condition where electrons reach some parts of the surface via interaction with the outer potential. This is what is commonly refered to as "mirror mode". (Top)

How can I make sure to hit the sample surface perpendicular with the incident beam?
At the transition between brightfield LEEM and mirror mode in low magnification two seperated images (e.g. spots with the beam cross-section shape) may appear. Change the beam incidence angle until they coincide. To achieve that, steering the beam and adjusting the sample voltage for MEM have to be iterated. (Top)

Website and Community
How can I become Part of the LEEM-User community?
If you own or use LEEM or PEEM, you are already a member of the community. The way to become an active member, however, is to let us know that you are interested and to send some information about your microscope and who is using it. (Top)

Who is Running this Webpage anyway?
Although this webpage is hosted on one of the servers of the University of Duisburg-Essen in Germany, it would not be possible if it wasn't for the international LEEM and PEEM community. Editorial work and updating of the page is now done by Frank Meyer zu Heringdorf. (Top)

 


 
 

University of Duisburg-Essen | AG Horn-von Hoegen


 
 



Au (5x3.2) Reconstruction Domains grown on Si(111). Courtesy of F. Meyer zu Heringdorf and R. Tromp, IBM.


Growth of Lead on Cu(111). Courtesy of Gary Kellog, Sandia



PEEM Images of Pentacene Islands on Si. Courtesy of F. Meyer zu Heringdorf and R. Tromp, IBM