Picosecond strain dynamics in Ge$_{2}$Sb$_{2}$Te$_{5}$ monitored by time-resolved x-ray diffraction

التفاصيل البيبلوغرافية
العنوان: Picosecond strain dynamics in Ge$_{2}$Sb$_{2}$Te$_{5}$ monitored by time-resolved x-ray diffraction
المؤلفون: Fons, Paul, Rodenbach, Peter, Mitrofanov, Kirill V., Kolobov, Alexander V., Tominaga, Junji, Shayduk, Roman, Giussani, Alessandro, Calarco, Raffaella, Hanke, Michael, Riechert, Henning, Simpson, Robert E., Hase, Muneaki
المصدر: Phys. Rev. B 90, 094305 (2014)
سنة النشر: 2014
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Materials Science
الوصف: Coherent phonons (CP) generated by laser pulses on the femtosecond scale have been proposed as a means to achieve ultrafast, non-thermal switching in phase-change materials such as Ge$_{2}$Sb$_{2}$Te$_{5}$(GST). Here we use ultrafast optical pump pulses to induce coherent acoustic phonons and stroboscopically measure the corresponding lattice distortions in GST using 100 ps x-ray pulses from the ESRF storage ring. A linear-chain model provides a good description of the observed changes in the diffraction signal, however, the magnitudes of the measured shifts are too large to be explained by thermal effects alone implying the presence of transient non-equilibrium electron heating in addition to temperature driven expansion. The information on the movement of atoms during the excitation process can lead to greater insight into the possibilities of using CP-induced phase-transitions in GST.
Comment: 7 pages, 4 figures, Phys. Rev. B, in press
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.90.094305
URL الوصول: http://arxiv.org/abs/1409.6888
رقم الانضمام: edsarx.1409.6888
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.90.094305