MRI: Acquisition of a Fast-Pulse-Laser for a Local Electrode Atom Probe Gregory B. Thompson, University of Alabama, DMR

1. MRI: Acquisition of a Fast-Pulse-Laser for a Local Electrode Atom Probe Gregory B. Thompson, University of Alabama, DMR 0722631 3nm Atom probe microscopy provides 3-dimensional reconstructions of individual atoms’ spatial location and identity. By forming a tip with a sharp radius (≈ 50-100 nm), atoms can be field evaporated off the surface and collected onto a position sensitive, mass spectrum detector. Historically, the field evaporation in atom probe was done by voltage pulsing, thus only conductive materials could be analyzed. The acquisition of the pulse laser allows thermal heating to assist field evaporation so that poor conductors, such as ceramics, and semiconductors can now be characterized by atom probe tomography. The University of Alabama will take shipment of a pico-second pulsed laser in late September 2007. This laser addition to the Local Electrode Atom Probe (LEAP) will expand the research capability of this tool for uses in several UA programs including: 1) Analysis of novel insulator barriers used for magnetic sensors 2) Semiconductor device structures 3) Oxidation in thermal barrier bond coatings 4) Catalysis films on non-conductive supports The following image is a LEAP atom map and concentration profile showing Pt segregation to the grain boundaries (arrows) in FePt for a next-generation magnetic hard-drive media thin film. The laser will allow similar reconstructions from traditionally difficult to analyze specimens. In particular to this research, the laser allows for the ability to characterize how oxide growth at the boundaries, used to magnetically decouple the grains, alters the segregation. Pt