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Mattern M, von Reppert A, Zeuschner SP, Herzog M, Pudell JE, Bargheer M. Concepts and use cases for picosecond ultrasonics with x-rays. PHOTOACOUSTICS 2023; 31:100503. [PMID: 37275326 PMCID: PMC10238750 DOI: 10.1016/j.pacs.2023.100503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 06/07/2023]
Abstract
This review discusses picosecond ultrasonics experiments using ultrashort hard x-ray probe pulses to extract the transient strain response of laser-excited nanoscopic structures from Bragg-peak shifts. This method provides direct, layer-specific, and quantitative information on the picosecond strain response for structures down to few-nm thickness. We model the transient strain using the elastic wave equation and express the driving stress using Grüneisen parameters stating that the laser-induced stress is proportional to energy density changes in the microscopic subsystems of the solid, i.e., electrons, phonons and spins. The laser-driven strain response can thus serve as an ultrafast proxy for local energy-density and temperature changes, but we emphasize the importance of the nanoscale morphology for an accurate interpretation due to the Poisson effect. The presented experimental use cases encompass ultrathin and opaque metal-heterostructures, continuous and granular nanolayers as well as negative thermal expansion materials, that each pose a challenge to established all-optical techniques.
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Affiliation(s)
- Maximilian Mattern
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | | | - Steffen Peer Zeuschner
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
| | - Marc Herzog
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - Jan-Etienne Pudell
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
- European XFEL, 22869 Schenefeld, Germany
| | - Matias Bargheer
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
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3
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Mattern M, Pudell JE, Dumesnil K, von Reppert A, Bargheer M. Towards shaping picosecond strain pulses via magnetostrictive transducers. PHOTOACOUSTICS 2023; 30:100463. [PMID: 36874592 PMCID: PMC9982602 DOI: 10.1016/j.pacs.2023.100463] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/12/2023] [Accepted: 02/14/2023] [Indexed: 06/07/2023]
Abstract
Using time-resolved x-ray diffraction, we demonstrate the manipulation of the picosecond strain response of a metallic heterostructure consisting of a dysprosium (Dy) transducer and a niobium (Nb) detection layer by an external magnetic field. We utilize the first-order ferromagnetic-antiferromagnetic phase transition of the Dy layer, which provides an additional large contractive stress upon laser excitation compared to its zero-field response. This enhances the laser-induced contraction of the transducer and changes the shape of the picosecond strain pulses driven in Dy and detected within the buried Nb layer. Based on our experiment with rare-earth metals we discuss required properties for functional transducers, which may allow for novel field-control of the emitted picosecond strain pulses.
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Affiliation(s)
- Maximilian Mattern
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - Jan-Etienne Pudell
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- European XFEL, 22869 Schenefeld, Germany
| | - Karine Dumesnil
- Institut Jean Lamour (UMR CNRS 7198), Université Lorraine, 54000 Nancy, France
| | | | - Matias Bargheer
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
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4
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Turenne D, Yaroslavtsev A, Wang X, Unikandanuni V, Vaskivskyi I, Schneider M, Jal E, Carley R, Mercurio G, Gort R, Agarwal N, Van Kuiken B, Mercadier L, Schlappa J, Le Guyader L, Gerasimova N, Teichmann M, Lomidze D, Castoldi A, Potorochin D, Mukkattukavil D, Brock J, Zhou Hagström N, Reid AH, Shen X, Wang XJ, Maldonado P, Kvashnin Y, Carva K, Wang J, Takahashi YK, Fullerton EE, Eisebitt S, Oppeneer PM, Molodtsov S, Scherz A, Bonetti S, Iacocca E, Dürr HA. Nonequilibrium sub-10 nm spin-wave soliton formation in FePt nanoparticles. SCIENCE ADVANCES 2022; 8:eabn0523. [PMID: 35363518 PMCID: PMC10938569 DOI: 10.1126/sciadv.abn0523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Magnetic nanoparticles such as FePt in the L10 phase are the bedrock of our current data storage technology. As the grains become smaller to keep up with technological demands, the superparamagnetic limit calls for materials with higher magnetocrystalline anisotropy. This, in turn, reduces the magnetic exchange length to just a few nanometers, enabling magnetic structures to be induced within the nanoparticles. Here, we describe the existence of spin-wave solitons, dynamic localized bound states of spin-wave excitations, in FePt nanoparticles. We show with time-resolved x-ray diffraction and micromagnetic modeling that spin-wave solitons of sub-10 nm sizes form out of the demagnetized state following femtosecond laser excitation. The measured soliton spin precession frequency of 0.1 THz positions this system as a platform to develop novel miniature devices.
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Affiliation(s)
- Diego Turenne
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Alexander Yaroslavtsev
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Xiaocui Wang
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | | | - Igor Vaskivskyi
- Complex Matter Department, Jožef Stefan Institute, Ljubljana, Slovenia
| | | | - Emmanuelle Jal
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, 75005 Paris, France
| | - Robert Carley
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Rafael Gort
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Naman Agarwal
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | | | | | | | | | - David Lomidze
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Andrea Castoldi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy
| | - Dimitri Potorochin
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
- Deutsches Elektronen-Synchrotron, 22607 Hamburg, Germany
- Institute of Experimental Physics, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
| | | | - Jeffrey Brock
- Center for Memory and Recording Research, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0401, USA
| | | | - Alexander H. Reid
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xijie J. Wang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Pablo Maldonado
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Yaroslav Kvashnin
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Karel Carva
- Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic
| | - Jian Wang
- Magnet Materials Unit, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Yukiko K. Takahashi
- Magnet Materials Unit, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Eric E. Fullerton
- Center for Memory and Recording Research, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0401, USA
| | - Stefan Eisebitt
- Max-Born-Institut, Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin, Germany
| | - Peter M. Oppeneer
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Serguei Molodtsov
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
- Institute of Experimental Physics, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
| | - Andreas Scherz
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Stefano Bonetti
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
- Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, 30172 Venice, Italy
| | - Ezio Iacocca
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
- Center for Magnetism and Magnetic Materials, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Hermann A. Dürr
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
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Bach N, Schäfer S. Ultrafast strain propagation and acoustic resonances in nanoscale bilayer systems. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:035101. [PMID: 34169119 PMCID: PMC8214470 DOI: 10.1063/4.0000079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Ultrafast structural probing has greatly enhanced our understanding of the coupling of atomic motion to electronic and phononic degrees-of-freedom in quasi-bulk materials. In bi- and multilayer model systems, additionally, spatially inhomogeneous relaxation channels are accessible, often governed by pronounced interfacial couplings and local excitations in confined geometries. Here, we systematically explore the key dependencies of the low-frequency acoustic phonon spectrum in an elastically mismatched metal/semiconductor bilayer system optically excited by femtosecond laser pulses. We track the spatiotemporal strain wave propagation in the heterostructure employing a discrete numerical linear chain simulation and access acoustic wave reflections and interfacial couplings with a phonon mode description based on a continuum mechanics model. Due to the interplay of elastic properties and mass densities of the two materials, acoustic resonance frequencies of the heterostructure significantly differ from breathing modes in monolayer films. For large acoustic mismatch, the spatial localization of phonon eigenmodes is derived from analytical approximations and can be interpreted as harmonic oscillations in decoupled mechanical resonators.
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Affiliation(s)
- N. Bach
- Institute of Physics, University of Oldenburg, 26129 Oldenburg, Germany
| | - S. Schäfer
- Institute of Physics, University of Oldenburg, 26129 Oldenburg, Germany
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7
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Mattern M, Pudell JE, Laskin G, von Reppert A, Bargheer M. Analysis of the temperature- and fluence-dependent magnetic stress in laser-excited SrRuO 3. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:024302. [PMID: 33786338 PMCID: PMC7994007 DOI: 10.1063/4.0000072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/23/2021] [Indexed: 06/07/2023]
Abstract
We use ultrafast x-ray diffraction to investigate the effect of expansive phononic and contractive magnetic stress driving the picosecond strain response of a metallic perovskite SrRuO3 thin film upon femtosecond laser excitation. We exemplify how the anisotropic bulk equilibrium thermal expansion can be used to predict the response of the thin film to ultrafast deposition of energy. It is key to consider that the laterally homogeneous laser excitation changes the strain response compared to the near-equilibrium thermal expansion because the balanced in-plane stresses suppress the Poisson stress on the picosecond timescale. We find a very large negative Grüneisen constant describing the large contractive stress imposed by a small amount of energy in the spin system. The temperature and fluence dependence of the strain response for a double-pulse excitation scheme demonstrates the saturation of the magnetic stress in the high-fluence regime.
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Affiliation(s)
- M. Mattern
- Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | | | - G. Laskin
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - A. von Reppert
- Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - M. Bargheer
- Author to whom correspondence should be addressed:. URL:http://www.uni-potsdam.de/udkm
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8
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Zeuschner SP, Mattern M, Pudell JE, von Reppert A, Rössle M, Leitenberger W, Schwarzkopf J, Boschker JE, Herzog M, Bargheer M. Reciprocal space slicing: A time-efficient approach to femtosecond x-ray diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014302. [PMID: 33532514 PMCID: PMC7822632 DOI: 10.1063/4.0000040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/21/2020] [Indexed: 06/07/2023]
Abstract
An experimental technique that allows faster assessment of out-of-plane strain dynamics of thin film heterostructures via x-ray diffraction is presented. In contrast to conventional high-speed reciprocal space-mapping setups, our approach reduces the measurement time drastically due to a fixed measurement geometry with a position-sensitive detector. This means that neither the incident (ω) nor the exit ( 2 θ ) diffraction angle is scanned during the strain assessment via x-ray diffraction. Shifts of diffraction peaks on the fixed x-ray area detector originate from an out-of-plane strain within the sample. Quantitative strain assessment requires the determination of a factor relating the observed shift to the change in the reciprocal lattice vector. The factor depends only on the widths of the peak along certain directions in reciprocal space, the diffraction angle of the studied reflection, and the resolution of the instrumental setup. We provide a full theoretical explanation and exemplify the concept with picosecond strain dynamics of a thin layer of NbO2.
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Affiliation(s)
| | - M. Mattern
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | | | - A. von Reppert
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - M. Rössle
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, BESSY II, 12489 Berlin, Germany
| | - W. Leitenberger
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - J. Schwarzkopf
- Leibniz-Institut für Kristallzüchtung, 12489 Berlin, Germany
| | - J. E. Boschker
- Leibniz-Institut für Kristallzüchtung, 12489 Berlin, Germany
| | - M. Herzog
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - M. Bargheer
- Authors to whom correspondence should be addressed: and
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