22 June 2006 Investigation of crystallization and amorphization dynamics of phase-change thin films using sub-nanosecond laser pulses
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Proceedings Volume 6282, Optical Data Storage 2006; 62820J (2006) https://doi.org/10.1117/12.685208
Event: Optical Data Storage 2006, 2006, Montréal, Canada
We report experimental results on amorphization and crystallization dynamics of reversible phase-change (PC) thin-film samples, GeSbTe and GeBiTe, for optical disk data storage. The investigation was conducted with subnanosecond laser pulses using a pump-and-probe configuration. Amorphization of the crystalline films could be achieved with a single subnanosecond laser pulse; the amorphization dynamics follows closely the temperature kinetics induced in the irradiated spot. As for crystallization of the samples initially in the amorphous state, a single subnanosecond pulse was found to be insufficient to fully crystallize the irradiated spot, but we could crystallize the PC film (in the area under the focused spot) by applying multiple short pulses. Our multi-pulse studies reveal that the GeSbTe crystallization is dominated by the growth of nuclei whose initial formation is slow but, once formed, their subsequent growth (under a sequence of subnanosecond pulses) happens quickly. In the case of GeBiTe samples, the crystalline nuclei appear to be present in the material initially, as they grow immediately upon illumination with laser pulses. Whereas our amorphous GeSbTe samples required ~200 pulses for full crystallization, for GeBiTe samples approximately 15 pulses sufficed.
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Khanh Kieu, Khanh Kieu, Kenji Narumi, Kenji Narumi, Masud Mansuripur, Masud Mansuripur, } "Investigation of crystallization and amorphization dynamics of phase-change thin films using sub-nanosecond laser pulses", Proc. SPIE 6282, Optical Data Storage 2006, 62820J (22 June 2006); doi: 10.1117/12.685208; https://doi.org/10.1117/12.685208

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