Structural and chemical characterization of crystals by TEM

Wolfgang Neumann 

Humboldt-Universit├Ąt, Newtonstr. 15, Berlin 12489, Germany

Abstract

Transmission electron microscopy (TEM) is a powerful tool to get a detailed insight into the materials characteristics. To elucidate the correlations between crystal structure and properties, including the nanochemistry (chemical composition and bonding), of advanced crystalline materials besides the imaging techniques of transmission electron microscopy, particularly high-resolution transmission electron microscopy (HRTEM), the microanalytical techniques of energy-dispersive X-ray spectroscopy (EDXS), electron energy loss spectroscopy (EELS) as well as microdiffraction and nanodiffraction techniques (e.g., convergent beam electron diffraction - CBED) can be applied. Moreover, dedicated sub-techniques are used to image the element distribution along a line (EDXS profile, series of EEL spectra) or two-dimensionally (X-ray mapping, energy-filtered TEM) at a lateral resolution of some nanometers (EDXS) or even on the sub-nm scale. In addition, the chemical bonding of the elements present in the transmitted volume is characterized by analysing electron energy loss near edge structures (ELNES). This additional information is available owing to the relatively high energy resolution of the EELS technique of about 0.5 - 1 eV.
For a reliable interpretation of TEM images , especially HRTEM images corresponding image simulations have to be carried out.
The fundamentals of the different TEM methods will be outlined. Furthermore, the potential of combined use of imaging and analytical TEM will be demonstrated for various modern crystalline materials of different dimensions.

 

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Presentation: invited oral at E-MRS Fall Meeting 2003, Pre-School of Symposium B, by Wolfgang Neumann
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-06-24 09:22
Revised:   2009-06-08 12:55