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SUMMARY:New opportunities and challenges for electron microscopy - Archie 
 Howie\, The Cavendish Laboratory\, University of Cambridge
DTSTART:20151029T160000Z
DTEND:20151029T170000Z
UID:TALK60038@talks.cam.ac.uk
CONTACT:Stephen Walley
DESCRIPTION:In recent decades\, electron microscopy has been radically tra
 nsformed by revolutionary advances in imaging (at the sub-Angstrom level w
 ith aberration-corrected  lenses)\, in spectroscopy (now approaching 10 me
 V) and in specimen preparation (with the focused ion beam). These advances
  allow many problems to be addressed more effectively but do not automatic
 ally deal with all the current challenges we face.  Now that further devel
 opment is largely left to the manufacturers and the traditional early stag
 e\, in-house innovation is not encouraged by research funding\, several le
 ss ambitious developments in instrumentation or technique which might be u
 seful have stayed in limbo.  Another problem arises from the modern micros
 cope designs where somewhat opaque software operating systems make it diff
 icult to implement older imaging procedures that might in some cases be mo
 re effective.\nMany samples with complex 3D structure are quite unsuitable
  for the 2D projection imaging widely used in high resolution imaging.  In
  some cases tomography has offered a solution and more recently depth sect
 ion imaging of dislocation core structure looks promising.  Simple diffrac
 tion contrast imaging has fallen out of fashion but has recently been revi
 ved for the observation of charge-discharge processes in batteries and may
  be important in drive towards phonon imaging.\nSecondary electron imaging
  can now reach < 1nm spatial resolution and shows some promise in characte
 rising the nanostructure of solar cells.  However we still lag behind the 
 surface scientists in spectroscopy of clean surfaces.  \nPioneering work o
 n picosecond scale time-resolved electron microscopy clearly demonstrated 
 the value of specimen pumping using tuned EM radiation but its wider poten
 tial for improved electron spectroscopy has not been actively taken up.  W
 e cannot of course avoid the black body radiation that bathes our specimen
 s giving rise to energy loss and gain processes that are now measureable. 
  At still lower energies\, the decoherence effects produced by Johnson noi
 se in the conducting components of the microscope present an intriguing ch
 allenge.\n
LOCATION:Mott Seminar Room\, Cavendish Laboratory
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