Magnetic Switching in Granular FePt Layers Promoted by Near-Field Laser Enhancement
| Autor: | Emmanuelle Jal, Tianmin Liu, Sebastian Carron, Zhao Chen, Joachim Stöhr, P. W. Granitzka, Padraic Shafer, Elke Arenholz, Eric E. Fullerton, Alexander X. Gray, L. Le Guyader, Alexander H. Reid, Hermann A. Dürr, Daniel J. Higley, Olav Hellwig, T. Chase, Georgi L. Dakovski, Yukiko Takahashi, Virat Mehta, Matthias C. Hoffman, William F. Schlotter, Jian Wang, Hendrik Ohldag, Matteo Savoini |
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| Přispěvatelé: | Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Fudan University [Shanghai], Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory (SLAC), Stanford University-Stanford University, Stanford University, Advanced Light Source [LBNL Berkeley] (ALS), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), HGST San Jose Research Center, Hard Condensed Matter (WZI, IoP, FNWI), IoP (FNWI), Quantum Matter and Quantum Information, Faculty of Science |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Physics::Optics FOS: Physical sciences Bioengineering Nanotechnology Near and far field 02 engineering and technology 01 natural sciences law.invention Magnetization law ultrafast magnetism 0103 physical sciences pump−probe General Materials Science Nanoscience & Nanotechnology [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] 010306 general physics ComputingMilieux_MISCELLANEOUS Condensed Matter - Materials Science Condensed matter physics Mechanical Engineering Materials Science (cond-mat.mtrl-sci) General Chemistry Coercivity X-ray scattering 021001 nanoscience & nanotechnology Condensed Matter Physics Magnetostatics Laser magnetic switching cond-mat.mtrl-sci Magnetic anisotropy pump-probe Femtosecond [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] 0210 nano-technology Excitation FePt |
| Zdroj: | Nano Letters Nano Letters, American Chemical Society, 2017, 17 (4), pp.2426-2432. ⟨10.1021/acs.nanolett.7b00052⟩ Nano letters, vol 17, iss 4 Nano Letters, 17(4), 2426-2432. American Chemical Society Granitzka, PW; Jal, E; Le Guyader, L; Savoini, M; Higley, DJ; Liu, T; et al.(2017). Magnetic Switching in Granular FePt Layers Promoted by Near-Field Laser Enhancement. Nano Letters, 17(4), 2426-2432. doi: 10.1021/acs.nanolett.7b00052. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/7559p8zx |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | © 2017 American Chemical Society. Light-matter interaction at the nanoscale in magnetic materials is a topic of intense research in view of potential applications in next-generation high-density magnetic recording. Laser-assisted switching provides a pathway for overcoming the material constraints of high-anisotropy and high-packing density media, though much about the dynamics of the switching process remains unexplored. We use ultrafast small-angle X-ray scattering at an X-ray free-electron laser to probe the magnetic switching dynamics of FePt nanoparticles embedded in a carbon matrix following excitation by an optical femtosecond laser pulse. We observe that the combination of laser excitation and applied static magnetic field, 1 order of magnitude smaller than the coercive field, can overcome the magnetic anisotropy barrier between "up" and "down" magnetization, enabling magnetization switching. This magnetic switching is found to be inhomogeneous throughout the material with some individual FePt nanoparticles neither switching nor demagnetizing. The origin of this behavior is identified as the near-field modification of the incident laser radiation around FePt nanoparticles. The fraction of not-switching nanoparticles is influenced by the heat flow between FePt and a heat-sink layer. |
| Databáze: | OpenAIRE |
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