1. NSLS-II Seminar

    "Real-time Synchrotron X-ray Studies of Growth and Materials Processes"

    Lan Zhou, Johns Hopkins University

    Friday, March 1, 2013, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

    Thin film growth and materials processes far away from equilibrium create both opportunities and challenges in controlling the microstructure and thus properties of materials. In this talk, I will demonstrate how to track the microstructural evolutions in-situ by utilizing synchrotron x-ray techniques to understand the fundamental mechanisms during those non-equilibrium processes. In the first part, I will present the real-time growth studies using x-ray scattering during Sputter Deposition and Pulsed Laser Deposition. The experiments were performed at NSLS X21 beamline. (1) Pressure-dependent transition from atoms to nanoparticles in magnetron sputtering: Effect on WSi2 film roughness and stress; (2) Lattice relaxation of dimer islands on Ge(001) during homoepitaxy by pulsed laser deposition. In the second part, I will present in-situ time-resolved x-ray studies of irreversible phase transformations during rapid heating of nanostructured metal multilayers: (1) sub-millisecond x-ray microdiffraction to track the phase transformation sequence and (2) millisecond angle-dispersive x-ray reflectivity to reveal initial stages of interdiffusion in multilayer reactions. The experiments were performed at APS ID-7B and CHESS A2 station.