Use este identificador para citar ou linkar para este item: http://hdl.handle.net/1843/80456
Tipo: Artigo de Periódico
Título: Precession damping in [Co60Fe40/Pt]5 multilayers with varying magnetic homogeneity investigated with femtosecond laser pulses
Autor(es): Mariana Andrade Boense Tavares
Leandro Hostalácio Freire de Andrade
Maximiliano Delany Martins
Gustavo Foscolo de Moura Gomes
Luis Eugenio Fernandez Outon
Franklin Massami Matinaga
Resumo: We report on the ultrafast magnetization dynamics of [Co60Fe40/Pt]5 multilayers studied with femtosecond laser pulses. The samples were grown at room temperature by DC magnetron sputtering with Ta capping and Pt buffer layers and present the same thickness and perpendicular magnetic anisotropy as determined by vibrating sample magnetometry. Controlled growth rate of the Pt buffer layer modified the anisotropy fields and magnetic domain sizes as measured by magnetic force microscopy (MFM). An estimation of the average magnetic domain sizes was obtained from the profile of the self-correlation transform of the MFM images. For multilayers having an average magnetic domain size of 490 nm, we report a damped precession of the magnetization which decays with a time constant of ∼100 ps and which has a frequency which varies from 8.4 GHz to 17.0 GHz as the external field increases from 192 mT to 398 mT. Fitting the precession dynamics with the Landau-Lifshitz-Gilbert equation we evaluated the damping α, which decreases from 0.18 to 0.05 with increasing magnetic domain sizes (127 nm to 490 nm). These α values are higher than for single layers suggesting an enhanced scattering and spin pumping effects from the Pt adjacent layers. In addition, the precession frequency increases from 2.04 GHz to 11.50 GHz as the anisotropy field of the multilayers increases from 6.5 kOe to 13.0 kOe. Finally, a comparative analysis between micromagnetic simulations and MFM images allowed us to determine the exchange stiffness (Aex) in the [Co60Fe40/Pt]5 multilayers.
Assunto: Anisotropia
Magnetismo
Idioma: eng
País: Brasil
Editor: Universidade Federal de Minas Gerais
Sigla da Instituição: UFMG
Departamento: ICX - DEPARTAMENTO DE FÍSICA
Tipo de Acesso: Acesso Aberto
Identificador DOI: https://doi.org/10.1063/1.5130458
URI: http://hdl.handle.net/1843/80456
Data do documento: 2019
metadata.dc.url.externa: https://pubs.aip.org/aip/adv/article/9/12/125322/1077172/Precession-damping-in-Co60Fe40-Pt-5-multilayers
metadata.dc.relation.ispartof: AIP Advances
Aparece nas coleções:Artigo de Periódico

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