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Ukleev V, Leroy L, Mincigrucci R, De Angelis D, Fainozzi D, Khatu NN, Paltanin E, Foglia L, Bencivenga F, Luo C, Ruske F, Radu F, Svetina C, Staub U. Transient grating spectroscopy on a DyCo 5 thin film with femtosecond extreme ultraviolet pulses. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:025101. [PMID: 38476300 PMCID: PMC10929737 DOI: 10.1063/4.0000223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/13/2024] [Indexed: 03/14/2024]
Abstract
Surface acoustic waves (SAWs) are excited by femtosecond extreme ultraviolet (EUV) transient gratings (TGs) in a room-temperature ferrimagnetic DyCo5 alloy. TGs are generated by crossing a pair of EUV pulses from a free electron laser with the wavelength of 20.8 nm matching the Co M-edge, resulting in a SAW wavelength of Λ = 44 nm. Using the pump-probe transient grating scheme in reflection geometry, the excited SAWs could be followed in the time range of -10 to 100 ps in the thin film. Coherent generation of TGs by ultrafast EUV pulses allows to excite SAW in any material and to investigate their couplings to other dynamics, such as spin waves and orbital dynamics. In contrast, we encountered challenges in detecting electronic and magnetic signals, potentially due to the dominance of the larger SAW signal and the weakened reflection signal from underlying layers. A potential solution for the latter challenge involves employing soft x-ray probes, albeit introducing additional complexities associated with the required grazing incidence geometry.
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Affiliation(s)
- Victor Ukleev
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Ludmila Leroy
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | | | - Dario De Angelis
- Elettra—Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Danny Fainozzi
- Elettra—Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | - Ettore Paltanin
- Elettra—Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Laura Foglia
- Elettra—Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | - Chen Luo
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Florian Ruske
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Florin Radu
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | | | - Urs Staub
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
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Mokkath JH, Nair R, Muhammed MM. Exploring intermixed magnetic nanoparticles: insights from atomistic spin dynamics simulations. Phys Chem Chem Phys 2024; 26:7020-7028. [PMID: 38345353 DOI: 10.1039/d3cp05281h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Binary nanoparticles, composed of both rare-earth elements with substantial magnetic properties and transition metals known for their high magnetic ordering temperatures, hold great promise as innovative materials for novel magnetic applications. In this study, we employ an atomistic spin dynamics framework to investigate how the magnetic properties change at finite temperatures in mixed NiGd nanoparticles. We specifically examine parameters such as saturation magnetization and spin-reorientation in relation to the nanoparticle's size, which ranges from 4 nm to 16 nm, and composition. Our findings reveal that Ni75Gd25 nanoparticles demonstrate exceptional magnetic properties at finite temperatures, marked by significantly increased saturation magnetizations and magnetic ordering temperatures. In contrast, nanoparticles containing 50% and 75% Gd contents exhibit notably reduced saturation magnetizations and magnetic ordering temperatures. Theoretical findings of our study shed light on the pivotal role that the Gd content plays in determining the magnetic behaviour at finite temperatures.
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Affiliation(s)
- Junais Habeeb Mokkath
- College of Integrative Studies, Abdullah Al Salem University (AASU), Block 3 Khaldiya, Kuwait.
| | - Remya Nair
- Department of Physics, Kuwait College of Science And Technology, 7th Ring Road, P.O. Box 27235, Kuwait
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