Local melting of Au/Ni thin films irradiated by femtosecond laser through GaN
- 21 Downloads
We found appropriate femtosecond laser irradiation conditions to locally melt Au/Ni double-layered thin films deposited on a GaN layer. The laser irradiation of the Au/Ni films was carried out through GaN and transmission electron microscopy revealed that GaN acted as a tough window to introduce laser pulses without suffering laser-induced damages. The Au/Ni double-layered thin films melted along the laser-irradiation lines and re-solidified into coarse particles containing an Au–Ni solid solution phase. On the other hand, in the area between laser-modified regions, the Au/Ni thin films retained the same morphology as the as-deposited state. The transition from the melted region to the unaffected area occurred in a narrow intermediate region. The present results show a possibility of a novel technique to site-specifically melt thin films to form a solid solution phase by femtosecond laser irradiation.
This work was partly supported by the Advanced Characterization Platform of the Nanotechnology Platform Japan sponsored by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT). We are grateful to Mr. Hiroshi Maeno of Kyushu University for his helpful support in transmission electron microscopy. Financial support from JSPS KAKENHI (Grant numbers 17H03147 and 17H05340) is also acknowledged.
- 12.T. Tamaki, W. Watanabe, K. Itoh, Opt. Exp. 14, 10468 (2006)Google Scholar
- 14.H. Okamoto, T.B. Massalski, in Binary Alloy Phase Diagrams, vol. 1, ed. by T. B. Massalski, J.L. Murray, L.H. Bennett, H. Baker (American Society for Metals, Metals Park, 1986), p. 288Google Scholar