Ultrafast low-temperature metal–insulator interface phonon dynamics and heat transport in a Pt/Gd3Fe5O12 heterostructure
Name
065101_1_4.0000778.pdf
Description
Published version
Size
3.07 MB
Format
Adobe PDF
Checksum (MD5)
27b322a98616c669aa9564245b799bad
Author(s)
Sri Gyan, Deepankar
Li, Ni
Chen, Zhantao
Geprägs, Stephan
Dietlein, Maxim
Gross, Rudolf
Sato, Takahiro
Sun, Yanwen
Hoffmann, Matthias C
Zhu, Diling
Date Issued
November 24, 2025
Journal
Structural Dynamics
Publisher
AIP Publishing
Citation
Deepankar Sri Gyan, Ni Li, Zhantao Chen, Stephan Geprägs, Maxim Dietlein, Rudolf Gross, Takahiro Sato, Yanwen Sun, Matthias C. Hoffmann, Diling Zhu, Daniel Haskel, Jörg Strempfer, Mingda Li, Danny Mannix, Paul G. Evans; Ultrafast low-temperature metal–insulator interface phonon dynamics and heat transport in a Pt/Gd3Fe5O12 heterostructure. Struct. Dyn. 1 December 2025; 12 (6): 065101.
Version
Final published version
Abstract
Interfacial thermal and acoustic phenomena have an important role in quantum science and technology, including in spintronic and spincaloritronic materials and devices. Simultaneous measurements of the low-temperature thermal and acoustic properties of a metal/insulator heterostructure reveal distinct dynamics in the characteristic phonon frequency ranges of acoustic and thermal transport. The measurements probed a heterostructure consisting of a thin film of Pt on the ferrimagnetic insulator gadolinium iron garnet (Gd3Fe5O12, GdIG) grown epitaxially on a gadolinium gallium garnet substrate. Ultrafast structural dynamics within the Pt layer were tracked using time-resolved ultrafast x-ray diffraction and analyzed to probe interfacial acoustic and thermal properties. The rapid heating of the Pt layer by a 400 nm wavelength femtosecond-duration optical pulse produced transient structural changes that provided the stimulus for these measurements. Rapid heating produced a broadband acoustic pulse that was partially reflected by the Pt/GdIG interface. Temporal frequencies up to 740 GHz, corresponding to angular frequencies of several THz, were detected in a wavelet analysis of the acoustic oscillations of the strain in the Pt layer. The structural results were analyzed to determine (i) the acoustic damping coefficient and phonon mean free path in Pt at frequencies of hundreds of GHz and (ii) the Grüneisen anharmonicity parameter. The thermal conductance of the Pt/GdIG interface was tracked using the slower, tens-of-picosecond-scale, dynamics of the initial cooling of the heated Pt layer. Analysis using a model based on the Boltzmann transport equation shows that the phonon transmission is lower at the phonon frequencies relevant to thermal transport than for subterahertz regime acoustics.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivatives
Persistent DSpace Link
DOI of Published Version
10.1063/4.0000778
