Abstract

GONZALEZ, Leonardo. ELECTRON DIFFRACTION PATTERNS INDEXATION WITH REACH OF EVERYONE AND ITS APPLICATIONS: ORTHOGONAL SYSTEMS. PART I. uct [online]. 2008, vol.12, n.49, pp.235-246. ISSN 1316-4821.

Some times when researching in material science an electron diffraction pattern is obtained. Most researchers with out enough proficiency in such task could find difficult to index such pattern, or if it is not so, then simple do it and the work in this area is considered finished. Researcher could be losing an excellent opportunity to find out new phases. The method employed in this paper consists in setting the reciprocal lattice of orthogonal unit cells and closed packed cell, because in such crystal systems most metals and metal alloys are crystallized. After that, a match between some reciprocal particular planes with the microscope screen is considered. When comparing singonía and sinaxia of the theoretical and experimental pattern the indices of the electron diffraction pattern is obtained. If we know the elementary chemical composition and the lattice parameter of the phase which is being studied then it is completely identified and some particular inference could take place in the industrial processes. Several examples are depicted to illustrate the method. This work has been divided into two parts: the first is devoted to orthogonal systems (cubic, tetragonal and orthorhombic) and the second to the hexagonal close packed. The method used for diffracting is the selected area diffraction, even though since 80s the micro-diffraction method has been developing.

Keywords : Diffraction Patterns; Electron Diffraction; Transmission Electron Microscope; Camera Constant; Reciprocal Lattice; Crystalline Systems; Miller Indexes.