Understanding Local Structures in Amorphous Oxides Through Raman Spectroscopy

ORAL

Abstract

We present a reformulated algorithm that enables ab initio calculations of Raman spectra for large-size systems, utilizing an external electric field and the Born effective charge to reduce the number of calculations. Using this approach, we compute the Raman spectra of amorphous GeO2 and Ti-doped GeO2 and demonstrate that our theoretical predictions closely align with experimentally observed features. Local structure and vibrational modes are captured. In addition, molecular dynamics simulations allow us to investigate structure features at 102 nm scale. Results from combined Raman spectroscopy and simulated annealing provide in-depth insight into short- and medium-range order. Structural characteristics of these amorphous oxides are discussed.

*This work is supported by the LIGO coating center funded by the U.S. National Science Foundation through grants PHY-2011776, PHY-2011770 and PHY-2309291. Computations were performed using the utilities of the National Energy Research Scientific Computing Center (NERSC) and the University of Florida Research Computing HiPerGator.

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Publication: 1. RASCBEC: RAman Spectroscopy Calculation via Born Effective Charge, submitted to Computer Physics Communications.
2. The network structure of amorphous TiO$_2$ doped GeO$_2$ via atomistic model and simulations of the Raman activity, in preparation.

Presenters

  • Rui Zhang

    • Northeastern University

Authors

  • Rui Zhang

    • Northeastern University

  • Ruth Osovsky

    • Colorado State University

  • Jun Jiang

    • Northeastern University

  • Ian Berry

    • Northeastern University

  • Kiran Prasai

    • Stanford University

  • Riccardo Bassiri

    • Stanford Univ

  • James Nathan Fry

    • University of Florida

  • CARMEN Susana MENONI

    • Colorado State University

  • Martin M Fejer

    • Stanford University

  • Hai-Ping Cheng

    • Northeastern University