Far-infrared Spectra of the Chalcogenide Alloy of the GST System of Composition Ge15Sb15Te70 in the Glassy and Crystalline State | Chapter 02 | Advances and Trends in Physical Science Research Vol. 1
Far-infrared
spectra of the chalcogenide alloy of the GST system of composition Ge15Sb15Te70
in the glassy and crystalline states have been measured and analysed in the
frequency range of 20–400 cm-1 at room temperature. The absorption in this
range is due to the phonon modes of the structural units of crystalline and
correlated librational vibrations (boson peak) of glassy alloy, which precede
the appearance of relaxation dynamics. IR spectroscopy is one of the most
frequently used spectroscopic tools for the crystals and amorphous materials
(including chalcogenide) study The vibrational assignments of various
absorption bands and the differences revealed in the spectra will make it
possible to more confidently elucidate the possible molecular mechanism of the
crystal-to-amorphous transition in other chalcogenide alloys. New details of
the crystal-to-amorphous transition scenario are suggested. The results, by the
example of the composition Ge15Sb15Te70,
demonstrate, that the use of far-IR spectroscopy has a clear potential to
characterise the local atomic structure and dynamics of the GST alloys. Here
experimental evidence is present that along with the change in bonding
mechanism there is change medium-range ordering upon crystallisation in GST
alloys. Further studies on the new GST materials will give the possibility to
improve the parameters of the already developed memory elements and will
provide additional information about the nature of the switching effect.
Biography of author(s)
Valery Ryzhov
Ioffe
Physical-Technical Institute, Russian Academy of Science, 194021 St-Petersburg,
Russia.
View Volume: https://doi.org/10.9734/BPI/atpsr/ed1
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