Strain Wave Pathway to Semiconductor-to-Metal Transition revealed by time resolved X-ray powder diffraction
| Autor: | Mariette, C., Lorenc, M., Cailleau, H., Collet, E., Guérin, L., Volte, A., Trzop, E., Bertoni, R., Dong, X., Lépine, B., Hernandez, O, Janod, E., Cario, L., Phuoc, V. Ta, Ohkoshi, S., Tokoro, H., Patthey, L., Babic, A., Usov, I., Ozerov, D., Sala, L., Ebner, S., Böhler, P., Keller, A, Oggenfuss, A., Zmofing, T., Redford, S., Vetter, S., Follath, R., Juranic, P., Schreiber, A., Beaud, P., Esposito, V., Deng, Y, Ingold, G., Chergui, M., Mancini, G. F., Mankowsky, R., Svetina, C., Zerdane, S., Mozzanica, A., Wulff, M., Levantino, M., Lemke, H., Cammarata, M. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/s41467-021-21316-y |
| Popis: | Thanks to the remarkable developments of ultrafast science, one of today's challenges is to modify material state by controlling with a light pulse the coherent motions that connect two different phases. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a macroscopic transformation pathway for the semiconducting-to-metal transition with large volume change in bistable Ti$_3$O$_5$ nanocrystals. Femtosecond powder X-ray diffraction allowed us to quantify the structural deformations associated with the photoinduced phase transition on relevant time scales. We monitored the early intra-cell distortions around absorbing metal dimers, but also long range crystalline deformations dynamically governed by acoustic waves launched at the laser-exposed Ti$_3$O$_5$ surface. We rationalize these observations with a simplified elastic model, demonstrating that a macroscopic transformation occurs concomitantly with the propagating acoustic wavefront on the picosecond timescale, several decades earlier than the subsequent thermal processes governed by heat diffusion. Comment: 30 pages (including supplementary text), 5 main figures, 9 supplementary figures; corrected author list |
| Databáze: | arXiv |
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