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Science, Vol. 308, No. 5720. (15 April 2005), pp. 392-395.
by A. M. Lindenberg, J. Larsson, K. Sokolowski-Tinten, et al.K. J. Gaffney, C. Blome, O. Synnergren, J. Sheppard, C. Caleman, A. G. Macphee, D. Weinstein, D. P. Lowney, T. K. Allison, T. Matthews, R. W. Falcone, A. L. Cavalieri, D. M. Fritz, S. H. Lee, P. H. Bucksbaum, D. A. Reis, J. Rudati, P. H. Fuoss, C. C. Kao, D. P. Siddons, R. Pahl, J. Als-Nielsen, S. Duesterer, R. Ischebeck, H. Schlarb, H. Schulte-Schrepping, Th Tschentscher, J. Schneider, D. von der Linde, O. Hignette, F. Sette, H. N. Chapman, R. W. Lee, T. N. Hansen, S. Techert, J. S. Wark, M. Bergh, G. Huldt, D. van der Spoel, N. Timneanu, J. Hajdu, R. A. Akre, E. Bong, P. Krejcik, J. Arthur, S. Brennan, K. Luening, J. B. Hastings
Abstract
The motion of atoms on interatomic potential energy surfaces is fundamental to the dynamics of liquids and solids. An accelerator-based source of femtosecond x-ray pulses allowed us to follow directly atomic displacements on an optically modified energy landscape, leading eventually to the transition from crystalline solid to disordered liquid. We show that, to first order in time, the dynamics are inertial, and we place constraints on the shape and curvature of the transition-state potential energy surface. Our measurements point toward analogies ...
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Physical Review Letters, Vol. 95, No. 12. (2005)
by K. J. Gaffney, A. M. Lindenberg, J. Larsson, et al.Sokolowski K. Tinten, C. Blome, O. Synnergren, J. Sheppard, C. Caleman, A. G. Macphee, D. Weinstein, D. P. Lowney, T. Allison, T. Matthews, R. W. Falcone, A. L. Cavalieri, D. M. Fritz, S. H. Lee, P. H. Bucksbaum, D. A. Reis, J. Rudati, A. T. Macrander, P. H. Fuoss, C. C. Kao, D. P. Siddons, R. Pahl, K. Moffat, Als J. Nielsen, S. Duesterer, R. Ischebeck, H. Schlarb, Schulte H. Schrepping, J. Schneider, D. von der Linde, O. Hignette, F. Sette, H. N. Chapman, R. W. Lee, T. N. Hansen, J. S. Wark, M. Bergh, G. Huldt, D. van der Spoel, N. Timneanu, J. Hajdu, R. A. Akre, E. Bong, P. Krejcik, J. Arthur, S. Brennan, K. Luening, J. B. Hastings
Abstract
The melting dynamics of laser excited InSb have been studied with femtosecond x-ray diffraction. These measurements observe the delayed onset of diffusive atomic motion, signaling the appearance of liquidlike dynamics. They also demonstrate that the root-mean-squared displacement in the [111] direction increases faster than in the [110] direction after the first 500 fs. This structural anisotropy indicates that the initially generated fluid differs significantly from the equilibrium liquid. ...
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Physical Review Letters, Vol. 98, No. 12. (2007)
by P. B. Hillyard, K. J. Gaffney, A. M. Lindenberg, et al.S. Engemann, R. A. Akre, J. Arthur, C. Blome, P. H. Bucksbaum, A. L. Cavalieri, A. Deb, R. W. Falcone, D. M. Fritz, P. H. Fuoss, J. Hajdu, P. Krejcik, J. Larsson, S. H. Lee, D. A. Meyer, A. J. Nelson, R. Pahl, D. A. Reis, J. Rudati, D. P. Siddons, Sokolowski K. Tinten, D. von der Linde, J. B. Hastings
posted to txrd by aloks
on 2008-10-15 19:06:03
Abstract
The ultrafast decay of the x-ray diffraction intensity following laser excitation of an InSb crystal has been utilized to observe carrier dependent changes in the potential energy surface. For the first time, an abrupt carrier dependent onset for potential energy surface softening and the appearance of accelerated atomic disordering for a very high average carrier density have been observed. Inertial dynamics dominate the early stages of crystal disordering for a wide range of carrier densities between the onset of crystal softening and the appearance of accelerated ...
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Physical Review Letters, Vol. 87, No. 22. (7 November 2001), 225701.
Abstract
Time-resolved x-ray diffraction with ultrashort (≈300 fs), multi-keV x-ray pulses has been used to study the femtosecond laser-induced solid-to-liquid phase transition in a thin crystalline layer of germanium. Nonthermal melting is observed to take place within 300–500 fs. Following ultrafast melting we observe strong acoustic perturbations evolving on a picosecond time scale. ...
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Nature, Vol. 422, No. 6929. (20 March 2003), pp. 287-289.
by Klaus Sokolowski-Tinten, Christian Blome, Juris Blums, et al.Andrea Cavalleri, Clemens Dietrich, Alexander Tarasevitch, Ingo Uschmann, Eckhard Forster, Martin Kammler, Michael Horn-Von-Hoegen, Dietrich von der Linde
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Physical Review Letters, Vol. 100, No. 13. (4 April 2008), pp. 135502-1-135502-5.
by A. M. Lindenberg, S. Engemann, K. J. Gaffney, et al.Sokolowski K. Tinten, J. Larsson, P. B. Hillyard, D. A. Reis, D. M. Fritz, J. Arthur, R. A. Akre, M. J. George, A. Deb, P. H. Bucksbaum, J. Hajdu, D. A. Meyer, M. Nicoul, C. Blome, Th, A. L. Cavalieri, R. W. Falcone, S. H. Lee, R. Pahl, J. Rudati, P. H. Fuoss, A. J. Nelson, P. Krejcik, D. P. Siddons, P. Lorazo, J. B. Hastings
Abstract
Femtosecond time-resolved small and wide angle x-ray diffuse scattering techniques are applied to investigate the ultrafast nucleation processes that occur during the ablation process in semiconducting materials. Following intense optical excitation, a transient liquid state of high compressibility characterized by large-amplitude density fluctuations is observed and the buildup of these fluctuations is measured in real time. Small-angle scattering measurements reveal snapshots of the spontaneous nucleation of nanoscale voids within a metastable liquid and support theoretical predictions of the ablation process. ...
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