| AVS 54th International Symposium | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuA |
| Session: | 3-Dimensional Characterization |
| Presenter: | C.F. Kisielowski, Lawrence Berkeley National Laboratory |
| Authors: | C.F. Kisielowski, Lawrence Berkeley National Laboratory F.R. Chen, National Tsing Hua University, Taiwan |
| Correspondent: | Click to Email |
Since several decades Transmission Electron Microscopy (TEM) is a primary tool for characterizing the inner structure of materials including interfaces and surfaces. A most limiting factor of the transmission-imaging mode comes with the projection of the probed crystal volume into one image plane, which causes loss of information about the materials structure along the electron beam direction. In recent years electron tomography was developed and successfully applied to soft and hard materials yielding the three dimensional materials structure with a resolution that can approach 1-2 nm.1,2 However, it is still impossible to achieve truly atomic resolution because radiation damage can limit the electron dose and because quantitative procedures need yet to be established that would allow recovering the materials structure at atomic resolution reliably from the recorded images. In order to achieve this goal it is essential to solve the phase problem and to remove effects that relate to the dynamic scattering of electrons in a solid. In this talk we describe current efforts that aim at reaching this goal. Our investigations build on recent hardware and software developments that relate to the DoE’s TEAM Project,3 which will provide a next generation of electron microscopes operating between 80 and 300 kV and providing deep sub Ångstrom resolution. We show that the phase problem is reliably solved and that dynamic scattering can be indeed inverted. As a result a full quantification of the samples mean inner potentials becomes possible, which can be used to determine the number of atoms in each imaged atom column together with its chemical composition. If such experiments are executed along a few zone axes it is possible to reconstruct the atomic structure of materials with atomic resolution.4 Experimental validations of the developed concept include gold surfaces and bi-crystals of Al:Cu.
1 C.-E. Hsieh, AR Leith a, C. A. Mannella, J. Frank, M. Marko, Journal of Structural Biology 153 (2006) 1-13
2 Q. Yang, J. Mardinly, C. Kübel, C. Nelson, C. Kisielowski, International Journal of Materials Research 97, (2006) 880-4
3 http://www.lbl.gov/LBL-Programs/TEAM/index.html
4 J.R. Jinschek, H.A. Calderon, K.J. Batenburg, V. Radmilovic, C. Kisielowski, Mat. Res. Soc. Symp. Proc. 839 (2005) 4.5.1 - 4.5.6.