New opportunities and challenges for electron microscopy

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• Archie Howie, The Cavendish Laboratory, University of Cambridge
• Thursday 29 October 2015, 16:00-17:00
• Mott Seminar Room, Cavendish Laboratory.

If you have a question about this talk, please contact Stephen Walley.

In recent decades, electron microscopy has been radically transformed by revolutionary advances in imaging (at the sub-Angstrom level with aberration-corrected lenses), in spectroscopy (now approaching 10 meV) and in specimen preparation (with the focused ion beam). These advances allow many problems to be addressed more effectively but do not automatically deal with all the current challenges we face. Now that further development is largely left to the manufacturers and the traditional early stage, in-house innovation is not encouraged by research funding, several less ambitious developments in instrumentation or technique which might be useful have stayed in limbo. Another problem arises from the modern microscope designs where somewhat opaque software operating systems make it difficult to implement older imaging procedures that might in some cases be more effective. Many 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 section imaging of dislocation core structure looks promising. Simple diffraction contrast imaging has fallen out of fashion but has recently been revived for the observation of charge-discharge processes in batteries and may be important in drive towards phonon imaging. Secondary electron imaging can now reach < 1nm spatial resolution and shows some promise in characterising the nanostructure of solar cells. However we still lag behind the surface scientists in spectroscopy of clean surfaces. Pioneering work on picosecond scale time-resolved electron microscopy clearly demonstrated the value of specimen pumping using tuned EM radiation but its wider potential for improved electron spectroscopy has not been actively taken up. We cannot of course avoid the black body radiation that bathes our specimens giving rise to energy loss and gain processes that are now measureable. At still lower energies, the decoherence effects produced by Johnson noise in the conducting components of the microscope present an intriguing challenge.

This talk is part of the Physics and Chemistry of Solids Group series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Cambridge Infectious Diseases
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room, Cavendish Laboratory
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• Physics and Chemistry of Solids Group
• School of Physical Sciences
• Thin Film Magnetic Talks

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