GOALI: Optical properties and visual appearance of naturally oxidized and anodized aluminum surfaces Sergey N. Rashkeev, Vanderbilt University, DMR EBSD imaging and finite element simulations of 6022-T4 aluminum alloy grain structure provide the strain distribution and surface roughness that affect light scattering. Au-implanted alumina (sand-colored) annealing by the free-electron laser at a wavelength 9 µm (dark colored bands). The size of the Au nanoparticles increases with annealing and an additional peak in optical spectra appears. The visual appearance and overall quality of a surface is affected by various features and defects (natural and artificially introduced by surface texturing, ion implantation, chemical processes, etc.) at different length scales. We combined a broad range of experimental and theoretical tools (including free-electron laser annealing, Z-contrast STEM imaging, first-principles calculations, and finite element simulations) to determine causal linkages between the defects and the macroscopic optical properties of Al surfaces. In particular, we investigated how the size and internal structure of implanted nanoparticles affect the surface color and how the plastic strain modifies light scattering in grain structures. Z-contrast STEM image shows that FeCo nanoparticles in Al 2 O 3 are not homogeneous - a phase separation of Fe and Co and/or incorporation of oxygen are possible.

Education, training, and development: One undergraduate (Lance Wilkinson, an African-American student from HBCU Alabama A&M University), two graduate students, and four postdocs (including Hispanic theory postdoc, Dr. Juan Carlos Idrobo) contributed to this work. During this summer, a Hispanic Vanderbilt physics major, Jeffrey Garcia, joined our project and was outstanding in his quick grasp of research opportunities. Jeffrey also participated in tours of Vanderbilt's nanoscience and engineering activities by two groups of Tennessee high-school students selected to participate in the Tennessee Technological University's program called the "President's Academy on Emerging Technologies." This project, in which we have participated during each of the past three years, has just been upgraded to a Governor's School on Emerging Technologies that will be funded by the state of Tennessee in the future. The School will have thirty selected students studying and doing research on emerging technologies each year, starting in the summer of On June 27, 2007, our collaborator in this NSF project, Professor Blair Tuttle from Penn State Behrend College (Erie, PA) who now spends a sabbatical year at Vanderbilt, presented a 2 hour workshop on nano-science and technology for high school students participating in the Penn State Behrend's MCE/WISE summer institute. He had about 40 students participate. They built structures out of paper to explore the importance of materials and scaling. After this project, Prof. Tuttle introduced nanoscience, discussed its basic tenets, and presented different applications. In particular, he presented this NSF project as a great example of using nano-science for solving industrial and technological problems. Optical properties and visual appearance of naturally oxidized and anodized aluminum surfaces Sergey N. Rashkeev, Vanderbilt University, DMR Jeffrey Garcia helps visiting high school students to set up a microscope to examine the monolayer microsphere colloid mask MCE/WISE students building a structure of paper to raise a book 20 cm.