http://pruffle.mit.edu/atomiccontrol/education/xray/xray_diff.php

try read above information from above site, it may help u...

but if we use radiation of wavelength below atomic level then we get better results..... 

try this page for an answer...

http://www.microscopy.ethz.ch/ED-XRD.htm

Yes,  we can,

but not the same electron beam, just a modified one.

It is a matter of penetration depth (x-rays vs electrons) and complexity and sensitivity of the experimental system, but also the handling. For the case of electrons please look for LEED on RHEED in the literature.