2020/12/18 by Daniela Zahn, Hélène Seiler, Seiler, H\'el\`ene +2
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Coupling (piping) #Crystallite #Crystallography #Diffraction #Electronic and Structural Properties of Oxides #Lattice (music) #Machine Learning in Materials Science #Materials science #Non-equilibrium thermodynamics #Phonon #Physics #Quantum mechanics #Semiconductor materials and devices #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/4.0000120
openalex publication_date 2020/12/18 · arxiv created 2021/11/17 · arxiv updated 2021/11/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Quantitative knowledge of electron-phonon coupling is important for many applications as well as for the fundamental understanding of nonequilibrium relaxation processes. Time-resolved diffraction provides direct access to this knowledge through its sensitivity to laser-induced lattice dynamics. Here, we present an approach for analyzing time-resolved polycrystalline diffraction data. A two-step routine is used to minimize the number of time-dependent fit parameters. The lattice dynamics are extracted by finding the best fit to the full transient diffraction pattern rather than by analyzing transient changes of individual Debye-Scherrer rings. We apply this approach to platinum, an important component of novel photocatalytic and spintronic applications, for which a large variation of literature values exists for the electron-phonon coupling parameter Gep. Based on the extracted evolution of the atomic mean squared displacement (MSD) and using a two-temperature model (TTM), we obtain Gep=(3.9±0.2)⋅1017\fracWm3\hspace1ptK (statistical error). We find that at least up to an absorbed energy density of 124\hspace2pt(J)/(cm3), Gep is not fluence-dependent. Our results for the lattice dynamics of platinum provide insights into electron-phonon coupling and phonon thermalization and constitute a basis for quantitative descriptions of platinum-based heterostructures in nonequilibrium conditions.