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A modified transient grating spectroscopy setup directly visualizes the full frequency- and direction-resolved elastodynamic Green's function of anisotropic crystal surfaces, matching the theoretical |G13| component in experimental angular

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2026-08-04 10:15 UTC pith:N6FEQBAA

load-bearing objection UTGS offers a real new view of the surface acoustic Green's function, but the 'identical intensities' claim needs quantitative support before publication. the 2 major comments →

arxiv 2510.10696 v2 pith:N6FEQBAA submitted 2025-10-12 cond-mat.mtrl-sci

Ultra-transient grating spectroscopy for visualization of surface acoustics

Tom\'a\v{s} Grabec (1) , Pavla Stoklasov\'a (1) , Krist\'yna Rep\v{c}ek (1) , Jakub Ku\v{s}n\'ir (1 , 2) , David Mare\v{s} (1) , Martin \v{S}ev\v{c}\'ik (1) , Petr Sedl\'ak (1)
show 6 more authors
Hanu\v{s} Seiner (1) ((1) Institute of Thermomechanics Czech Academy of Sciences Prague (2) Faculty of Nuclear Sciences Physical Engineering Czech Technical University in Prague)
This is my paper
classification cond-mat.mtrl-sci
keywords transient grating spectroscopysurface acoustic wavesGreen's functionelastic anisotropyultra-transientangular dispersion mapsphotoacousticselastodynamics
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper introduces ultra-transient grating spectroscopy (UTGS), a modification of transient grating spectroscopy that captures the first few nanoseconds of the surface response after a laser pulse. It claims this early-window signal contains near-field thermoacoustic phenomena—oscillations with lifetimes an order of magnitude shorter than ordinary surface-acoustic-wave standing patterns—and that the resulting angular dispersion maps replicate the frequency-domain elastodynamic Green's function component |G13| in full detail. The authors demonstrate agreement on nickel and iron aluminide single crystals with different elastic anisotropy, and show that the far-field signal alone (after truncating the first ~25 ns) reduces to standing-wave resonances. If correct, the method turns a single surface scan into a rich, contactless measurement of anisotropic elastic behavior.

Core claim

The central discovery is that the elastodynamic response of an anisotropic free surface, as encoded in the first tens of nanoseconds after a spatially harmonic thermoacoustic source is applied, can be optically detected and equated with a single component of the surface Green's function. Experimentally, UTGS maps—frequency versus propagation direction—match calculated |G13(k∥,ω)| maps for every studied cut, including fine features such as sharp 'cliffs' at limiting bulk-wave velocities, narrow 'acoustic sinks' where energy is steered into the bulk, and disconnected segments arising from slowness-surface caustics. The paper attributes these features to conversions of partial waves between eva

What carries the argument

The mechanism is the transient grating itself: two crossed pump laser pulses create a spatially harmonic thermoacoustic source—an array of line-like expanding regions—which launches surface and bulk acoustic waves with a well-defined surface wave vector. The probe beam diffracts off the resulting surface ripple, and with heterodyne phase tuned for out-of-plane sensitivity the signal is proportional to the out-of-plane displacement component, hence to |G13| of the elastodynamic Green's function. The partial-wave construction of the Green's function (decomposing the response into three phase-matched solutions of the Christoffel equation) provides the theoretical maps, while Ritz-Rayleigh eigen

Load-bearing premise

The load-bearing premise is that the heterodyne-detected diffracted signal is proportional to the out-of-plane surface displacement component u3, and therefore to |G13|, so that if in-plane motions, thermal lensing, or electronic/optical artifacts contribute appreciably in the first ~25 ns, the experimental maps are not a pure visualization of |G13|.

What would settle it

Record a UTGS map with the heterodyne phase rotated by 90° so the detection is maximally sensitive to in-plane rather than out-of-plane displacement; if the sharp cliffs, sinks, and caustic features persist with comparable contrast, the signal is not dominated by the out-of-plane component and the identification with |G13| is falsified.

Watch this falsifier. Get emailed when new claim-graph text bears on it.

If this is right

  • Angular dispersion maps from a single free surface can be used to extract anisotropic elastic constants, with the possibility of direct algebraic determination on high-symmetry cuts.
  • Because the excitation is spatially harmonic, wave-vector orientation is well defined, unlike point-source phonon-imaging approaches; measurements need no cryogenic conditions.
  • The maps expose near-field phenomena—evanescent-to-homogeneous partial-wave conversions, surface skimming waves, acoustic sinks, and caustic segments—that are invisible to conventional far-field TGS.
  • The local measurement spot (roughly 800×800 µm², reducible lower) allows probing individual grains, graded materials, or thin films; all-optical operation enables in-situ characterization under external stimuli.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the |G13| mapping holds, the same experimental approach could be extended by phase-sensitive detection of other Green's function components, potentially yielding the full displacement tensor from a single setup rather than only the out-of-plane part.
  • The 'acoustic sink' bands—frequency windows where surface energy couples into bulk beams—might be exploitable in phononic device design, e.g. as frequency-selective couplers, if the slowness-surface geometry can be engineered through composition or patterning.
  • The shallow near-field penetration of the ultra-transient response suggests a route to depth-profiling near-surface modifications (damage, coatings) by analyzing how the early-time signal evolves as the pump wavelength is varied.
  • Since the paper notes the maps are rich enough that other Green's function components may add little elastic-constant information, the technique could shift materials characterization from discrete wave-speed fitting to full-image matching between calculated and measured maps.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. The paper presents ultra-transient grating spectroscopy (UTGS), a modified transient grating spectroscopy arrangement that records the first few tens of nanoseconds of the thermoacoustic response, and uses it to produce angular-dispersion maps of the FFT amplitude of the out-of-plane surface displacement. These maps are compared with the |G13| component of the elastodynamic Green's function calculated from published elastic constants for Ni and Fe3Al single crystals. The authors report striking visual agreement, and support the near-field origin of the detailed features by time-domain truncation experiments, Ritz-Rayleigh eigenmode calculations of the far-field response, and partial-wave analysis of the Green's function features (cliffs, acoustic sinks, caustics). They propose UTGS as a tool for contactless characterization of anisotropic solids and, potentially, for direct inversion of elastic constants.

Significance. If the central claim holds, UTGS would be a genuinely new capability: a direct experimental visualization of the frequency-domain surface Green's function component |G13|, with wave-vector selectivity and without the need for cryogenic temperatures. The work combines a well-established optical technique with a previously overlooked early-time signal and a clear theoretical framework. The Green's-function calculations are not fitted to the new data — they use elastic constants from the literature (including the authors' earlier work, but not from this dataset) — and the truncation experiments provide a convincing internal check that the detailed features originate in the ultra-transient part of the signal. The paper is clearly written and the figures are informative. The main weakness is that the quantitative link between the measured FFT amplitude and the calculated |G13| is not established: no deconvolution of the laser-pulse spectrum or the detection bandwidth is described, no misfit metric is given, and the claim that 'relative intensities of all features are identical' rests on visual comparison. Because this proportionality is the load-bearing assumption behind 'visualization

major comments (2)
  1. [Results and Discussion, first paragraph after experimental description; Figure 1(f,g)] The claim 'the shapes and relative intensities of all features are identical, up to some experimental scatter' is central to the paper's title and abstract, but it is supported only by visual inspection. The experimental A is the FFT of a time-domain signal produced by a 0.53 ns FWHM pump pulse; the Gaussian amplitude spectrum of such a pulse rolls off by roughly 30% between 200 and 700 MHz, and the 10 kHz–1 GHz photodiode/amplifier response is not stated to be flat. No deconvolution or spectral normalization is described in Methods or the Supplementary material. Consequently, relative intensities of features at different wavespeeds are not directly comparable to the frequency-domain |G13|. I recommend either (i) dividing the experimental spectra by the measured or independently characterized instrument response, (ii) restricting the comparison to feature positions and morphologies, expl
  2. [Methods, 'Transient grating spectroscopy'; Results and Discussion, 'The thermoacoustic source...'] The measurement is assumed to be proportional to the out-of-plane displacement u3, and hence to |G13|, based on 'the heterodyne phase was adjusted for optimal sensitivity to the out-of-plane displacements using a phase retarder.' This is a manual adjustment and the manuscript provides no calibration or control experiment demonstrating that in-plane motion, thermal lensing, or electronic artifacts in the first ~25 ns do not contaminate the signal. The truncation experiments in Fig. 2 show that the detailed features originate in the ultra-transient region, but they do not by themselves establish that the surviving amplitude is proportional to |G13|. I suggest adding a control measurement with a known isotropic or weakly anisotropic sample, or a systematic scan of the heterodyne phase, to quantify the residual sensitivity to other displacement components and to source/detector nonlinearitie
minor comments (5)
  1. [Concluding Remarks] The phrase 'opens a novel, previously explored pathway' appears self-contradictory; presumably 'previously unexplored' was intended.
  2. [Methods, 'Transient grating spectroscopy'] The wavelength calibration is said to be 'calibrated using a known material', but the material is not identified. Please specify which material and reference value were used.
  3. [Eq. (7)] The notation on the left-hand side omits the angular frequency: it should read |G13(k∥,ω)| if the right-hand side is evaluated at ±k∥ for the same ω. The text immediately after the equation is clear, but the notation should be consistent.
  4. [Data availability] The data are currently accessible only through a review token and will be made open only if the paper is accepted. For a paper whose central claim relies on visual comparisons, I would strongly encourage making the data and the processing scripts publicly available in the repository from the date of acceptance (or earlier), so that readers can perform the quantitative comparisons suggested above.
  5. [Figure 2(f) discussion] The statement that the Ritz-Rayleigh spectrum 'perfectly matches' the truncated map in Fig. 2(d) is also visual. Since this is a secondary supporting check, a brief quantitative statement (e.g., frequency residuals for the peaks marked SAW, L, T) would increase confidence without much effort.

Circularity Check

0 steps flagged

No significant circularity: the UTGS maps are fresh experimental data compared with independently computed |G13| maps using prior, non-fitted elastic constants.

full rationale

The paper's derivation chain is: UTGS records the FFT amplitude A of the diffracted probe signal; the signal is assumed (following external TGS literature, Refs. 9 and 29) to be sensitive to out-of-plane surface displacement, hence to the G13 component of the elastodynamic Green's function; |G13| is then computed independently by the partial-wave solution of Christoffel's equation using elastic constants taken from prior publications (Refs. 7 and 54); and the experimental and computed maps are compared. No step is defined in terms of the other, and no parameter is fitted to the UTGS data to force the agreement. The elastic constants cited from Refs. 7 and 54 are prior measurements, not quantities tuned or extracted in the present paper, so this is not a fitted input renamed as a prediction. The Ritz-Rayleigh method and other numerical details are cited from the authors' earlier work, but those are methodological citations with stated assumptions and are not used to define the central result. The main validation weakness is qualitative: the 0.53 ns pump pulse spectrum is not deconvolved and no quantitative misfit metric is given, so the proportionality A proportional to |G13| is asserted rather than rigorously proven. That is a correctness/validation concern, not circularity. No quoted equation reduces to its own input by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 6 axioms · 0 invented entities

The central claim rests on standard elastodynamic theory and on material parameters (elastic constants, densities, crystallographic orientations) taken from prior literature, including two self-cited papers. No parameters are fitted to the experimental UTGS maps in this work; the wavelength is calibrated using a known material. The main modeling assumptions are the linear proportionality of the detected signal to |G13| and the idealization of the sample as a homogeneous anisotropic half-space.

axioms (6)
  • domain assumption The TGS diffraction signal is proportional to the out-of-plane surface displacement and thus to the G13 component of the elastodynamic Green's function.
    Stated in Results and Discussion: 'the measured response to the TGS source should be described by the G13 component of the Green's function'. The heterodyne phase is adjusted to maximize sensitivity to out-of-plane displacement. This linear mapping underpins all comparisons between experiment and theory.
  • domain assumption The thermoacoustic source can be modeled as a spatially harmonic, temporally impulsive surface force that is weak enough to avoid ablation and nonlinear effects.
    Standard TGS model; the paper uses pulse energies below the ablation limit and a 0.53 ns pulse, but the ideal impulsive line-force model is assumed when computing |G13|. This is invoked in 'Results and Discussion' and Methods.
  • domain assumption The elastic constants, densities, and crystallographic orientations of the samples are as given in the literature and XRD measurements.
    The Green's function calculations use c11, c12, c44 for Ni (Ref 7) and Fe3Al (Ref 54), densities, and orientations from MaTecK or Laue XRD. If these inputs are wrong, the predicted maps would shift and the claimed agreement would be misleading.
  • standard math The partial-wave formalism (Every et al.) correctly solves the elastodynamic response of a homogeneous anisotropic half-space to a harmonic surface load.
    Used in Methods (Eqs. 2-7) to compute |G13|. This is standard continuum mechanics; no free parameters.
  • standard math The Ritz-Rayleigh eigenmode calculation with domain depth d=70λ and Legendre order N=180 converges to the true eigenmodes of the periodic half-space domain.
    Used in Figure 2(e-f) to identify far-field resonances. The paper justifies d=70λ for anisotropy and N=180, but convergence is not demonstrated with a systematic check.
  • domain assumption The measured surface is a homogeneous, stress-free, anisotropic half-space over the ~0.5-0.8 mm measurement spot.
    Samples are polished; Fe3Al cuts come from a polycrystalline piece, so each spot is assumed to be a single grain with uniform orientation. In-plane inhomogeneity would blur the angular maps.

pith-pipeline@v1.3.0-alltime-deepseek · 15610 in / 14075 out tokens · 113966 ms · 2026-08-04T10:15:15.395176+00:00 · methodology

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read the original abstract

Ultrasonic wave propagation across material surfaces reveals essential information about the materials' elastic behavior. The elastodynamic response of the surface is characterized by the Green's function that fully captures all its direction-dependent and frequency-dependent features. Here we present the first direct experimental visualization of the frequency-domain angular-resolved Green's function, including all its complex details resulting from elastic anisotropy. We achieve this visualization using transient grating spectroscopy (TGS), which is a method otherwise well established for measuring Rayleigh-type surface acoustic waves (SAWs). But here we focus on early-time thermoacoustic phenomena in the TGS experiment, revealing that, along with the transient standing-wave patterns of SAWs, there also emerge oscillations with at least an order of magnitude shorter lifetimes. These oscillations superpose into dynamic displacement patterns that are transient with respect to the classical transient timescales in TGS; the optical diffraction signal from these 'ultra-transient' gratings enables capturing the surface acoustic response with exceptional detail, and the resulting experimental angular dispersion maps strikingly replicate the theoretical frequency-domain Green's functions. By utilizing this feature, ultra-transient grating spectroscopy (UTGS) becomes a powerful tool for detailed contactless characterization of anisotropic solids, opening new pathways for studying single-crystalline or nanostructured materials.

Figures

Figures reproduced from arXiv: 2510.10696 by 2), (2) Faculty of Nuclear Sciences, Czech Academy of Sciences, Czech Technical University in Prague), David Mare\v{s} (1), Hanu\v{s} Seiner (1) ((1) Institute of Thermomechanics, Jakub Ku\v{s}n\'ir (1, Krist\'yna Rep\v{c}ek (1), Martin \v{S}ev\v{c}\'ik (1), Pavla Stoklasov\'a (1), Petr Sedl\'ak (1), Physical Engineering, Prague, Tom\'a\v{s} Grabec (1).

Figure 1
Figure 1. Figure 1: TGS experiments on cuts of anisotropic single crystals. [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: The ultra-transient origin of detailed features in TGS maps. [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Detailed features in the UTGS map explained by analysis of the Green’s function. [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

56 extracted references · 43 canonical work pages

  1. [1]

    Wave Motion50, 1197–1217, DOI: 10.1016/j.wavemoti.2013.02.007 (2013)

    Every, A.et al.Bulk and surface acoustic wave phenomena in crystals: Observation and interpretation. Wave Motion50, 1197–1217, DOI: 10.1016/j.wavemoti.2013.02.007 (2013)

    work page doi:10.1016/j.wavemoti.2013.02.007 2013

  2. [2]

    Measurement of the near-surface elastic properties of solids and thin supported films.Meas

    Every, A. Measurement of the near-surface elastic properties of solids and thin supported films.Meas. Sci. Tech.13, R21, DOI: 10.1088/0957-0233/13/5/201 (2002)

    work page doi:10.1088/0957-0233/13/5/201 2002

  3. [3]

    G., Kim, K

    Every, A. G., Kim, K. Y . & Maznev, A. A. The elastodynamic response of a semiinfinite anisotropic solid to sudden surface loading.J. Acoust. Soc. Am.102, 1346–1354, DOI: 10.1121/1.420053 (1997)

    work page doi:10.1121/1.420053 1997

  4. [4]

    Rogers, J. A.et al.Optical system for rapid materials characterization with the transient grating technique: Application to nondestructive evaluation of thin films used in microelectronics.Appl. Phys. Lett.71, 225–227, DOI: 10.1063/1.119506 (1997)

    work page doi:10.1063/1.119506 1997

  5. [5]

    & Rogers, J

    Maznev, A., Nelson, K. & Rogers, J. Optical heterodyne detection of laser-induced gratings.Opt. Lett.23, 1319–1321, DOI: 10.1364/OL.23.001319 (1998)

    work page doi:10.1364/ol.23.001319 1998

  6. [6]

    Hofmann, F., Short, M. P. & Dennett, C. A. Transient grating spectroscopy: An ultrarapid, non- destructive materials evaluation technique.MRS Bull.44, 392–402, DOI: 10.1557/mrs.2019.104 (2019)

    work page doi:10.1557/mrs.2019.104 2019

  7. [7]

    Mech.DOI: 10.1007/s11340-021-00698-6 (2021)

    Stoklasová, P.et al.Laser-ultrasonic characterization of strongly anisotropic materials by transient grating spectroscopy.Exp. Mech.DOI: 10.1007/s11340-021-00698-6 (2021)

    work page doi:10.1007/s11340-021-00698-6 2021

  8. [8]

    & Dieulesaint, E.Elastic Waves in Solids II: Generation, Acousto-optic Interaction, Applications(Springer Science & Business Media, 2001)

    Royer, D. & Dieulesaint, E.Elastic Waves in Solids II: Generation, Acousto-optic Interaction, Applications(Springer Science & Business Media, 2001)

    2001

  9. [9]

    A., Akthakul, A

    Maznev, A. A., Akthakul, A. & Nelson, K. A. Surface acoustic modes in thin films on anisotropic substrates.J. Appl. Phys.86, 2818–2824, DOI: 10.1063/1.371130 (1999)

    work page doi:10.1063/1.371130 1999

  10. [10]

    A.et al.Phase-controlled, heterodyne laser-induced transient grating measurements of thermal transport properties in opaque material.J

    Johnson, J. A.et al.Phase-controlled, heterodyne laser-induced transient grating measurements of thermal transport properties in opaque material.J. Appl. Phys.111, DOI: 10.1063/1.3675467 (2012)

    work page doi:10.1063/1.3675467 2012

  11. [11]

    Huberman, S.et al.Unifying first-principles theoretical predictions and experimental measurements of size effects in thermal transport in SiGe alloys.Phys. Rev. Mater.1, 054601, DOI: 10.1103/Phys RevMaterials.1.054601 (2017)

    doi:10.1103/phys 2017

  12. [12]

    Dennett, C. A. & Short, M. P. Thermal diffusivity determination using heterodyne phase insensitive transient grating spectroscopy.J. Appl. Phys.123, DOI: 10.1063/1.5026429 (2018)

    work page doi:10.1063/1.5026429 2018

  13. [13]

    Properties of Elastic Surface Waves

    Farnell, G. Properties of Elastic Surface Waves. InPhysical Acoustics, vol. 6, 109–166, DOI: 10.1016/B978-0-12-395666-8.50017-8 (Elsevier, 1970). 14/18

    work page doi:10.1016/b978-0-12-395666-8.50017-8 1970

  14. [14]

    A., Maznev, A

    Rogers, J. A., Maznev, A. A., Banet, M. J. & Nelson, K. A. Optical Generation and Characterization of Acoustic Waves in Thin Films: Fundamentals and Applications.Annu. Rev. Mater. Sci.30, 117–157, DOI: 10.1146/annurev.matsci.30.1.117 (2000)

    work page doi:10.1146/annurev.matsci.30.1.117 2000

  15. [15]

    Vega-Flick, A.et al.Vibrational dynamics of a two-dimensional microgranular crystal.Phys. Rev. B 96, 024303, DOI: 10.1103/PhysRevB.96.024303 (2017)

    work page doi:10.1103/physrevb.96.024303 2017

  16. [16]

    Grabec, T.et al.Guided acoustic waves in thin epitaxial films: Experiment and inverse problem solution for niti.Ultrasonics138, DOI: 10.1016/j.ultras.2023.107211 (2024)

    arXiv 2023

  17. [17]

    P., Wylie, A

    Weaver, C., Stapelberg, M., Short, M. P., Wylie, A. & Artalejo, E. B. Automated transient grating spectroscopy mapping and signal control for large samples.Rev. Sci. Instruments95, 074902, DOI: 10.1063/5.0202262 (2024)

    work page doi:10.1063/5.0202262 2024

  18. [18]

    J., Založnik, A., Patino, M

    Simmonds, M. J., Založnik, A., Patino, M. I., Baldwin, M. J. & Boechler, N. An increased accuracy laser-induced transient grating spectroscopy analysis method for probing near surface thermal dif- fusivity with gigahertz frequency instrumentation.AIP Adv.14, 105226, DOI: 10.1063/5.0196820 (2024)

    work page doi:10.1063/5.0196820 2024

  19. [19]

    J.et al.Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation.Meas

    Smith, R. J.et al.Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation.Meas. Sci. Technol.25, 055902, DOI: 10.1088/0957-0233/25/5/055902 (2014)

    work page doi:10.1088/0957-0233/25/5/055902 2014

  20. [20]

    J., Sharples, S

    Patel, R., Li, W., Smith, R. J., Sharples, S. D. & Clark, M. Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy.Scripta Materialia140, 67–70, DOI: 10.1016/j.scriptamat.2017.07.003 (2017)

    work page doi:10.1016/j.scriptamat.2017.07.003 2017

  21. [21]

    Siegman, A. E. Bragg diffraction of a Gaussian beam by a crossed-Gaussian volume grating*.J. Opt. Soc. Am.67, 545–550, DOI: 10.1364/JOSA.67.000545 (1977)

    work page doi:10.1364/josa.67.000545 1977

  22. [22]

    & Short, M

    Dennett, C. & Short, M. Time-resolved, dual heterodyne phase collection transient grating spec- troscopy.Appl. Phys. Lett.110, DOI: 10.1063/1.4983716 (2017)

    work page doi:10.1063/1.4983716 2017

  23. [23]

    Sermeus, J., Sinha, R., Vanstreels, K., Vereecken, P. M. & Glorieux, C. Determination of elastic properties of a MnO2 coating by surface acoustic wave velocity dispersion analysis.J. Appl. Phys. 116, 023503, DOI: 10.1063/1.4885427 (2014)

    work page doi:10.1063/1.4885427 2014

  24. [24]

    Hofmann, F.et al.Non-contact measurement of thermal diffusivity in ion-implanted nuclear materials. Sci. Rep.5, 1–7, DOI: 10.1038/srep16042 (2015)

    doi:10.1038/srep16042 2015

  25. [25]

    A.et al.Increase in elastic anisotropy of single crystal tungsten upon He-ion implantation measured with laser-generated surface acoustic waves.Appl

    Duncan, R. A.et al.Increase in elastic anisotropy of single crystal tungsten upon He-ion implantation measured with laser-generated surface acoustic waves.Appl. Phys. Lett.109, DOI: 10.1063/1.4964709 (2016)

    work page doi:10.1063/1.4964709 2016

  26. [26]

    Instruments Methods Phys

    Trachanas, E.et al.Thermal diffusivity variation assessment on Radio-Frequency Quadrupole Cu-OF copper due to proton irradiation.Nucl. Instruments Methods Phys. Res. Sect. B: Beam Interactions with Mater. Atoms539, 179–189, DOI: 10.1016/j.nimb.2023.04.002 (2023)

    work page doi:10.1016/j.nimb.2023.04.002 2023

  27. [27]

    Reza, A.et al.Non-contact, non-destructive mapping of thermal diffusivity and surface acoustic wave speed using transient grating spectroscopy.Rev. Sci. Instruments91, 054902, DOI: 10.1063/5.0003742 (2020). 28.Zener, C.Elasticity and Anelasticity of Metals(University of Chicago Press, 1948)

    work page doi:10.1063/5.0003742 2020

  28. [29]

    W., Skurk, H., Maznev, A

    Käding, O. W., Skurk, H., Maznev, A. A. & Matthias, E. Transient thermal gratings at surfaces for thermal characterization of bulk materials and thin films.Appl. Phys. A Mater . Sci. Process.61, 253–261, DOI: 10.1007/BF01538190 (1995). 15/18

    work page doi:10.1007/bf01538190 1995

  29. [30]

    Landa, M.et al.Modal resonant ultrasound spectroscopy for ferroelastics.Appl. Phys. A96, 557–567, DOI: 10.1007/s00339-008-5047-4 (2009)

    work page doi:10.1007/s00339-008-5047-4 2009

  30. [31]

    & Landa, M

    Stoklasová, P., Sedlák, P., Seiner, H. & Landa, M. Forward and inverse problems for surface acoustic waves in anisotropic media: A Ritz-Rayleigh method based approach.Ultrasonics56, 381–9, DOI: 10.1016/j.ultras.2014.09.004 (2015)

    work page doi:10.1016/j.ultras.2014.09.004 2014

  31. [32]

    R., Crowhurst, J

    Stoddart, P. R., Crowhurst, J. C., Every, A. G. & Comins, J. D. Measurement precision in surface Brillouin scattering.J. Opt. Soc. Am. B15, 2481, DOI: 10.1364/JOSAB.15.002481 (1998)

    work page doi:10.1364/josab.15.002481 1998

  32. [33]

    & Comins, J

    Every, A., Sumanya, C., Mathe, B., Zhang, X. & Comins, J. Optimized determination of elastic constants of crystals and their uncertainties from surface Brillouin scattering.Ultrasonics69, 273–278, DOI: 10.1016/j.ultras.2016.02.004 (2016)

    work page doi:10.1016/j.ultras.2016.02.004 2016

  33. [34]

    & Planes, A

    Mañosa, L. & Planes, A. Materials with Giant Mechanocaloric Effects: Cooling by Strength.Adv. Mater.29, 1603607, DOI: 10.1002/adma.201603607 (2017)

    work page doi:10.1002/adma.201603607 2017

  34. [35]

    & Planes, A

    Xiao, F., Bucsek, A., Jin, X., Porta, M. & Planes, A. Giant elastic response and ultra-stable elastocaloric effect in tweed textured Fe-Pd single crystals.Acta Materialia223, 117486, DOI: 10.1016/j.actamat.2021.117486 (2022)

    arXiv 2021

  35. [36]

    Hou, H.et al.Fatigue-resistant high-performance elastocaloric materials made by additive manufac- turing.Science366, 1116–1121, DOI: 10.1126/science.aax7616 (2019)

    work page doi:10.1126/science.aax7616 2019

  36. [37]

    Energy1, 1–6, DOI: 10.1038/nenergy.20 16.134 (2016)

    Tušek, J.et al.A regenerative elastocaloric heat pump.Nat. Energy1, 1–6, DOI: 10.1038/nenergy.20 16.134 (2016)

    work page doi:10.1038/nenergy.20 2016

  37. [38]

    Caloric Effects in Ferroic Materials: New Concepts for Cooling.Energy Technol.6, 1394–1396, DOI: 10.1002/ente.201800201 (2018)

    Fähler, S. Caloric Effects in Ferroic Materials: New Concepts for Cooling.Energy Technol.6, 1394–1396, DOI: 10.1002/ente.201800201 (2018)

    work page doi:10.1002/ente.201800201 2018

  38. [39]

    N., Nunn, W., Jalan, B

    Bucsek, A. N., Nunn, W., Jalan, B. & James, R. D. Energy Conversion by Phase Transformation in the Small-Temperature-Difference Regime.Annu. Rev. Mater. Res.50, 283–318, DOI: 10.1146/annu rev-matsci-082019-021824 (2020)

    work page doi:10.1146/annu 2020

  39. [40]

    & Müllner, P

    Lindquist, P., Chernenko, V ., Cesari, E. & Müllner, P. Mechanical energy conversion to electricity through periodically stress-induced martensitic transformation in Co-Ni-Ga.Scripta Materialia236, 115667, DOI: 10.1016/j.scriptamat.2023.115667 (2023)

    arXiv 2023

  40. [41]

    & Shilo, D

    Faran, E. & Shilo, D. Ferromagnetic Shape Memory Alloys—Challenges, Applications, and Experi- mental Characterization.Exp. Tech.40, 1005–1031, DOI: 10.1007/s40799-016-0098-5 (2016)

    work page doi:10.1007/s40799-016-0098-5 2016

  41. [42]

    & Fähler, S

    Heczko, O., Seiner, H. & Fähler, S. Coupling between ferromagnetic and ferroelastic transitions and ordering in Heusler alloys produces new multifunctionality.MRS Bull.47, 618–627, DOI: 10.1557/s43577-022-00354-x (2022)

    doi:10.1557/s43577-022-00354-x 2022

  42. [43]

    Glorieux, C.et al.On the character of acoustic waves at the interface between hard and soft solids and liquids.The J. Acoust. Soc. Am.110, 1299–1306, DOI: 10.1121/1.1396333 (2001)

    work page doi:10.1121/1.1396333 2001

  43. [44]

    P.Imaging Phonons: Acoustic Wave Propagation in Solids(Cambridge University Press, 1998)

    Wolfe, J. P.Imaging Phonons: Acoustic Wave Propagation in Solids(Cambridge University Press, 1998)

    1998

  44. [45]

    Sugawara, Y ., Wright, O. B. & Matsuda, O. Direct access to the dispersion relations of multiple anisotropic surface acoustic modes by Fourier image analysis.Appl. Phys. Lett.83, 1340–1342, DOI: 10.1063/1.1602151 (2003)

    work page doi:10.1063/1.1602151 2003

  45. [46]

    Tachizaki, T.et al.Scanning ultrafast Sagnac interferometry for imaging two-dimensional surface wave propagation.Rev. Sci. Instruments77, 043713, DOI: 10.1063/1.2194518 (2006). 16/18

    work page doi:10.1063/1.2194518 2006

  46. [47]

    G., Grill, W

    Pluta, M., Every, A. G., Grill, W. & Kim, T. J. Fourier inversion of acoustic wave fields in anisotropic solids.Phys. Rev. B67, 094117, DOI: 10.1103/PhysRevB.67.094117 (2003)

    work page doi:10.1103/physrevb.67.094117 2003

  47. [48]

    On the propagation of tremors over the surface of an elastic solid.Philos

    Lamb, H. On the propagation of tremors over the surface of an elastic solid.Philos. Trans. R. Soc. Lond.203, 1–42 (1904)

    1904

  48. [49]

    Musgrave, M. J. P.Crystal acoustics: introduction to the study of elastic waves and vibrations in crystals(Holden-Day, San Francisco, 1970)

    1970

  49. [50]

    Nature638, 965–971, DOI: 10.1038/s41586-024-08583-7 (2025)

    Song, Y .et al.A lightweight shape-memory alloy with superior temperature-fluctuation resistance. Nature638, 965–971, DOI: 10.1038/s41586-024-08583-7 (2025)

    work page doi:10.1038/s41586-024-08583-7 2025

  50. [51]

    Mater.2406672, DOI: 10.1002/adma.202406672 (2024)

    Repˇcek, K.et al.Compliant Lattice Modulations Enable Anomalous Elasticity in Ni–Mn–Ga Martensite.Adv. Mater.2406672, DOI: 10.1002/adma.202406672 (2024)

    doi:10.1002/adma.202406672 2024

  51. [52]

    Verstraeten, B.et al.Determination of thermoelastic material properties by differential heterodyne detection of impulsive stimulated thermal scattering.Photoacoustics3, 64–77, DOI: 10.1016/j.pacs.2 015.05.001 (2015)

    work page doi:10.1016/j.pacs.2 2015

  52. [53]

    Every, A. G. Supersonic surface acoustic waves on the 001 and 110 surfaces of cubic crystals.J. Acoust. Soc. Am.138, 2937–2944, DOI: 10.1121/1.4934557 (2015)

    work page doi:10.1121/1.4934557 2015

  53. [54]

    Kušnír, J.et al.Apparent anisotropic thermal diffusivity measured in cubic single crystals by transient grating spectroscopy.J. Appl. Phys.133, DOI: 10.1063/5.0136850 (2023)

    work page doi:10.1063/5.0136850 2023

  54. [55]

    & Tang, L

    Deng, J., Xu, Y ., Guasch, O., Gao, N. & Tang, L. Nullspace technique for imposing constraints in the rayleigh–ritz method.J. Sound Vib.527, 116812, DOI: 10.1016/j.jsv.2022.116812 (2022)

    arXiv 2022

  55. [56]

    & Landa, M

    Sedlák, P., Seiner, H., Zídek, J., Janovská, M. & Landa, M. Determination of all 21 independent elastic coefficients of generally anisotropic solids by resonant ultrasound spectroscopy: Benchmark examples.Exp. Mech.54, 1073–1085, DOI: 10.1007/s11340-014-9862-6 (2014)

    work page doi:10.1007/s11340-014-9862-6 2014

  56. [57]

    & Seiner, H

    Grabec, T., Sedlák, P. & Seiner, H. Application of the Ritz—Rayleigh method for Lamb waves in extremely anisotropic media.Wave Motion96, 102567, DOI: 10.1016/j.wavemoti.2020.102567 (2020). Acknowledgments This work has been financially supported by Czech Science Foundation [Project No. 22-13462S] and by the Operational Programme Johannes Amos Comenius of ...

    arXiv 2020