20 September 2004 Watching a solid shake itself apart: an atomic view of melting
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Proceedings Volume 5448, High-Power Laser Ablation V; (2004) https://doi.org/10.1117/12.549429
Event: High-Power Laser Ablation, 2004, Taos, New Mexico, United States
Abstract
The picosecond barrier to high brightness electron pulses has been broken. Electron diffraction harbors great potential for providing atomic resolution to structural changes at critical points — a real-time view of atomic motions during structural transitions. Femtosecond electron pulses of sufficient number density to execute nearly single-shot structure determinations are needed. This requirement places severe constraints on the electron pulse propagation. A new photoactivated electron gun design has been developed based on an N-body numerical simulation and mean-field calculation of the electron wavepacket propagation that is capable of less than 600 femtosecond electron pulses with high enough brightness to provide structural details in the small shot number limit. Time-resolved diffraction studies with this new instrument have focused on strongly driven solid-liquid phase transitions of aluminum as a model problem of a structural transition. The signal to noise and available diffraction orders were sufficiently high to give direct access to fluctuations leading to the disordering or melting process and the associated radial distribution function. This work gives atomic level details of a solid-liquid phase transition, i.e., we can literally watch the atoms move during melting. The promise of atomically resolving transition state processes is at hand and applications along this line will be discussed.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. J. Dwayne Miller, R. J. Dwayne Miller, Jason R. Dwyer, Jason R. Dwyer, Christoph T. Hebeisen, Christoph T. Hebeisen, Robert E. Jordan, Robert E. Jordan, Bradley J. Siwick, Bradley J. Siwick, } "Watching a solid shake itself apart: an atomic view of melting", Proc. SPIE 5448, High-Power Laser Ablation V, (20 September 2004); doi: 10.1117/12.549429; https://doi.org/10.1117/12.549429
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