Sept. 25, 2012
Quantitative HAADF (q-HAADF) for DigitalMicrograph
Higashimatsuyama, Saitama, Japan (Sept. 25, 2012): HREM Research Inc. introduced qHAADF (Quantitative HAADF) at the recent EMC2012 in Manchester, UK. qHAADF makes possible atomic column-to-column compositional analysis of materials from the analysis of High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM) images using Gatanfs DigitalMicrograph.
qHAADF is based on the analysis of normalized integrated intensities by a method developed by Sergio I. Molina of University of Cadiz. From the automatic finding of intensity peaks, the method measures integrated intensities in selected areas corresponding to projected atomic columns. From these intensities, based on either the use of experimental HAADF images taken from calibrated samples or areas from the sample with known composition, compositions of each atomic column are obtained and mapped.
In addition to this function, another remarkable possibilities of this software are the efficient finding and mapping of interstitial atoms in materials, the counting of atoms in each analyzed atomic column, and the estimation of column-to-column compositional maps in materials by using simulated HAADF images as a reference for this determination. The combined use of qHAADF with PPA (Peak Pairs Analysis) software constitutes a powerful tool for the analysis of both the strain and composition of materials with sub-nanometer spatial resolution.@
About HREM Research Inc.
Founded in 2001, HREM Research Inc. specializes in developing products and services that enhance High-Resolution Electron Microscopy (HREM). Dr. Kazuo Ishizuka, the founder of a company has established the whole technique for HREM image simulation. Thus, a company's flagship product, Mac/WinHREM, is a world leading HREM image simulation software. Currently, HREM Research Inc. is actively working on making useful techniques to be available for the HREM community. For more information, visit http://www.hremresearch.com or contact firstname.lastname@example.org.
HREM Research Inc.
14-48 Matsukazedai, Higashimatsuyama
(Left) Map of normalized integrated intensities measured from a HAADF-STEM image of a double InAs-GaAs epitaxial layer. These intensities are directly related to the composition in each atomic column of the material.
(Right) Map of Bi content (expressed as number of atoms) in each atomic column of a GaAs1-xBix epitaxial layer, which has been obtained from the analysis of integrated intensities of HAADF images.