Laser-induced diffusion decomposition in Fe-V thin-film alloys

• Autor(a) principal: Polushkin, N. I.
• Data de Publicação: 2015
• Outros Autores: Duarte, A. C., Conde, O., Alves, E., Barradas, N. P., García-García, A., Kakazei, G. N., Ventura, J. O., Araújo, J. P., Oliveira, Vitor, Vilar, R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/5911
• topic: Metallic alloys; Phase separation; Laser quenching; Ferromagnetism

We investigate the origin of ferromagnetism induced in thin-film (similar to 20 nm) Fe-V alloys by their irradiation with subpicosecond laser pulses. We find with Rutherford backscattering that the magnetic modifications follow a thermally stimulated process of diffusion decomposition, with formation of a-few-nm-thick Fe enriched layer inside the film. Surprisingly, similar transformations in the samples were also found after their long-time (similar to 10(3) s) thermal annealing. However, the laser action provides much higher diffusion coefficients (similar to 4 orders of magnitude) than those obtained under standard heat treatments. We get a hint that this ultrafast diffusion decomposition occurs in the metallic glassy state achievable in laser-quenched samples. This vitrification is thought to be a prerequisite for the laser-induced onset of ferromagnetism that we observe. 2014 Elsevier B.V. All rights reserved.