High precision detection of the change in intermediate range order of amorphous thin films due to annealing

ORAL

Abstract

Future gravitational wave detectors, such as Advanced LIGO +, will be limited in sensitivity by thermal noise associated with mechanical loss in the detectors’ amorphous mirror coatings. In order to reduce mechanical loss, we aim to understand the atomic level structures responsible for it and take a directed design approach to suggest improved coatings. Through studies on thin films of amorphous zirconia-doped-tantala (ZrO2-Ta2O5), a potential coating for LIGO mirrors, we present high precision detection of the change in the intermediate range order (IRO) as a function of post-deposition annealing, using grazing incidence x-ray scattering measurements carried out at the Stanford Synchrotron Radiation Lightsource. For the first time, our atomic modeling based on x-ray scattering data is able to capture the changes in IRO. We show that the primary structural units (PSUs), which are disordered oxygen octahedra centered around the metal atoms, remain largely unchanged after annealing. We explain the observed structural changes in terms of the IRO, specifically, the change in metal-oxygen-metal bond angles at the bridging oxygen sites, and the way neighboring PSUs share bridging oxygens. Finally, we discuss correlations between the observed changes in the IRO and mechanical loss.

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Presenters

  • Kiran Prasai

    E. L. Ginzton Laboratory, Stanford University, Ginzton Laboratory, Stanford University, Applied Physics, Stanford University, E. L. Ginzton Laboratory, Stanford

Authors

  • Kiran Prasai

    E. L. Ginzton Laboratory, Stanford University, Ginzton Laboratory, Stanford University, Applied Physics, Stanford University, E. L. Ginzton Laboratory, Stanford

  • Jun Jiang

    Department of Physics and Quantum Theory Project, University of Florida, Department of Physics and the Quantum Theory Project, University of Florida

  • Alec Mishkin

    Department of Physics and Quantum Theory Project, University of Florida

  • Sarah Hoback

    Department of Physics, American University

  • David A Drabold

    Department of Physics and Astronomy, Ohio University, Ohio University

  • Eric Keith Gustafson

    LIGO Laboratory, California Institute of Technology, Pasadena, CA, USA, California Institute of Technology, LIGO Laboratory, California Institute of Technology, LIGO Lab, California Institute of Technology

  • Mariana Fazio

    Department of Electrical and Computer Engineering and NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, Fort Collins, CO, USA, Department of Electrical and Computer Engineering, Colorado State University

  • Gregory M Harry

    Department of Physics, American University, Physics, American University

  • Apurva Mehta

    Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, SLAC National Accelerator Laboratory, SLAC

  • Carmen Susana Menoni

    Colorado State Univ, Department of Electrical and Computer Engineering and NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, Fort Collins, CO, USA, Department of Electrical and Computer Engineering, Colorado State University

  • Carl Lévesque

    Université de Montréal, Montréal, Quebec, Canada, Department of Physics, Université de Montréal

  • Ian MacLaren

    School of Physics & Astronomy, University of Glasgow

  • Steven D Penn

    Department of Physics, Hobart and William Smith Colleges

  • François Schiettekatte

    Université de Montréal, Montréal, Quebec, Canada, Department of Physics, Université de Montréal

  • Rosalie Shink

    Department of Physics, Université de Montréal

  • Badri Shyam

    University of Dayton Research Institute

  • Gabriele Vajente

    California Institute of Technology, LIGO Lab, California Institute of Technology

  • Hai-Ping Cheng

    Department of Physics and Quantum Theory Project, University of Florida, Department of Physics and the Quantum Theory Project, University of Florida

  • Martin Fejer

    Department of Applied Physics, Ginzton Laboratory, Stanford University, Stanford, CA, USA, Stanford University, Applied Physics, Stanford University, E. L. Ginzton Laboratory, Stanford University, Ginzton Laboratory, Stanford University, E. L. Ginzton Laboratory, Stanford

  • Riccardo Bassiri

    Department of Applied Physics, Ginzton Laboratory, Stanford University, Stanford, CA, USA, Applied Physics, Stanford University, E. L. Ginzton Laboratory, Stanford University, Ginzton Laboratory, Stanford University, E. L. Ginzton Laboratory, Stanford