| AVS 60th International Symposium and Exhibition | |
| Atom Probe Tomography Focus Topic | Wednesday Sessions |
| Session AP+AS+MI+NS+SS-WeA |
| Session: | APT and FIM Analysis of Catalysts and Nanoscale Materials |
| Presenter: | A. Devaraj, Pacific Northwest National Laboratory |
| Authors: | A. Devaraj, Pacific Northwest National Laboratory R.J. Colby, Pacific Northwest National Laboratory D.E. Perea, Pacific Northwest National Laboratory S.A. Thevuthasan, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Metal-dielectric composite materials are ubiquitous in several important engineering applications ranging from catalysis to semiconductor devices. The technological advances in such fields heavily depend upon the development of three-dimensional characterization capabilities that can accurately identify composition and structure at sub-nanometer spatial resolution and ppm-level composition sensitivity. Atom probe tomography (APT) has already demonstrated its potential in three-dimensional characterization of bulk metals and alloys, however the theoretical understanding of the evaporation behavior of dielectrics and metal-dielectric composites, as well as possible artifacts during laser assisted APT, is still at its infancy. 3D transmission electron microscopy (TEM) tomography on the other hand is currently restricted by long acquisition times and reconstruction artifacts. A correlative TEM-APT approach can help in extending the applicability of APT analysis and TEM beyond the current boundaries by providing not only complementary information but also a deeper understanding of the possible artifacts. This presentation will focus on such a correlated TEM-APT approach to investigate the field evaporation behavior of metal dielectric composites with metallic nanoparticles embedded inside oxides as well as planar structures with metallic thin films on single crystalline oxide substrates. Aberration-corrected TEM high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) were used to image the APT samples before and after APT analysis. STEM imaging after interrupted APT analysis was used to capture snapshots of evolving tip shape. Such understanding, when combined with novel APT reconstruction processing, can greatly aid in expanding the capabilities of APT analysis to novel complex heterogeneous metal-dielectric composite materials.