New Instrumentation for TEM Electron Diffraction Structure Analysis: Electron Diffractometry Combined with Beam Precession

Abstract

Electron diffractometry has been used in the past in combination with electron diffraction cameras (EDC) and has been prooved very succesfull for electron crystalography work; by measuring electron diffraction intensities with high precision (up to 1 %) structure resolution of many minerals with even refined light atoms like H,O positions has been resolved this way. We are reporting for the first time a new generation of electron diffractometry equipment (combined with beam precession technique to avoid dynamical interactions). The device could be pontentially interfaced to any commercial TEM in order to measure precisely ED data and resolve structures of nm size. The technique has a strong potential for electron crystallography as any voltage TEM may be used (> 100 kv);preliminary results are presented with a case study where light lithium atoms are revealed in a spinel structure.