Departmental Seminar

Electron Crystallography and Precession Electron Diffraction Applications in TEΜ: from crystal structure determination to orientation imaging and strain mapping at nm scale

Mr Vrettos Stelliou

An introductory seminar, on advanced electron crystallographic methods on the Transmission Electron Microscope (TEM). The basic technical solution used as a platform is based on the early work by Vincent and Midgley in Bristol UK (1994) that developed the Precession Electron Diffraction (PED) technique. 

Important applications for Electron crystallography that use PED as an essential tool are the recently developed 3D PED diffraction tomography technique for structural solutions of previously unknown structures, and the ASTAR technique where is possible to obtain orientation and phase maps at 1-3 nm resolution for a variety of materials. The technique can be complementary to the Dynamic Transmission Electron Microscope (DTEM) system which combines a conventional TEM with two laser systems and achieves 15 ns temporal and nm spatial resolution, as required to study rapid solidification processes in metal and alloy thin films.

Precession diffraction has been recently successfully applied to obtain strain mapping analysis of several semiconductor materials at 1-4 nm resolution. The technique is very easy to use at any TEM and provides very fast and accurate data (same order of magnitude as dark field holography) without any need to index diffraction patterns.

Vrettos Stelliou holds a Physics Degree from University of Athens, Greece and a Masters of Biomedical Engineering from U.N.S.W, Sydney, Australia.

He served the Hellenic Navy as a Technical Officer for two years and worked as a Professional Officer for the Australian Public Service (TGA).

He entered the International Private Sector from June 1998 as a Sales Manager, responsible for Philips’ Scientific Instrumentation in Greece (exclusive) and Cyprus on a case dependent basis. During his career, he has collaborated with several companies mainly in the Nanotechnology field and received extensive training relevant to Technical/Legal & Regulatory/Sales & Managerial Issues. Since 2007 he has been working as an Area Manager/Application Specialist/Consultant undertaking diverse projects around the globe with a current record of more than 30 countries.

His interests expand into other fields as he is currently working also on a Doctoral course in Professional and Intercultural Communication.

Date & time

Wed 12 Apr 2017, 3–4pm



Link Bldg Seminar room 414


Members of RSPE welcome