This technique has been the basis of my research interests since 1970. At that time the concept was new in Britain, and electron microscopes were not capable of atomic resolution but limited to 3-5Å. Molecules, particularly organic molecules, were within this resolution range, and my research workers and myself commenced investigating the feasibility of using the electron microscope to study organic crystals.
Some years later we were successful in producing the first images of aromatic hydrocarbons and work on this direct imaging continues at present, with studies on liquid crystals and organic charge transfer compounds being subjects under investigation. This work has extended into image processing, phase extension and molecular modelling which are the basis of collaborative projects with other members of the Chemistry Department. We have now established the methods for the use of the electron microscope for determining molecular structures with molecules containing up to 60 atoms and now plan to extend this work to much larger systems, and molecules of different composition including inorganic structures such as zeolites and organo-metallic semiconductors.
Fundamental work continues on epitaxial crystal growth and electron beam radiation damage, which are essential studies if the microscope is to be exploited to its fullest capability. This is particularly important now that our latest instrument is capable of 1.8Å resolution, and structures are directly interpretable at the atomic level.