AVS 59th Annual International Symposium and Exhibition
    Applied Surface Science Wednesday Sessions
       Session AS+NS+SS+TF-WeA

Paper AS+NS+SS+TF-WeA4
Atom Probe Tomography of Complex Heterogeneous Low Dimensional Materials

Wednesday, October 31, 2012, 3:00 pm, Room 20

Session: 3D Imaging & Nanochemical Analysis - Part 2 (2:00-3:20 pm)/ Advanced Data Analysis and Instrument Control (4:00-6:00 pm)
Presenter: S. Thevuthasan, Pacific Northwest National Laboratory
Authors: S. Thevuthasan, Pacific Northwest National Laboratory
A. Devaraj, Pacific Northwest National Laboratory
R. Colby, Pacific Northwest National Laboratory
D.E. Perea, Pacific Northwest National Laboratory
V. Subramanian, Pacific Northwest National Laboratory
V. Shutthanandan, Pacific Northwest National Laboratory
Correspondent: Click to Email
EMSL, a national scientific user facility of the DOE, is developing a comprehensive chemical imaging capability combining atom probe tomography with high resolution (scanning) transmission electron microscopy(HR(S)TEM) and high resolution Rutherford back scattering spectrometry (HRRBS) to provide solutions to problems pertaining to energy and environmental applications. We will emphasize on a chemical imaging effort aimed at atomically-resolved composition and structural analysis of low dimensional materials such as nanowires and embedded metal nanoparticles highlighting the benefits and challenges for APT. A unique benefit of APT is the ability to characterize the ppm level concentration and distribution of dopants across semiconducting nanowire heterojunctions. The preferential incorporation of dopants at specific atomic facets at the heterojunction interface in Si-Ge nanowires can only be characterized by using APT. Another important class of low dimensional materials includes embedded metal nanoparticles in oxides with applications in catalysis, sensors and optoelectronic applications. In order to extent APT analysis capability to such materials a cross correlative approach of combining APT with aberration corrected HRSTEM is employed. The results from the model system of ion beam synthesized Au and Ag nanoparticles embedded in MgO will be presented.