TY - JOUR
T1 - Femtosecond x-ray diffraction reveals a liquid–liquid phase transition in phase-change materials
AU - Zalden, Peter
AU - Quirin, Florian
AU - Schumacher, Mathias
AU - Siegel, Jan
AU - Wei, Shuai
AU - Koc, Azize
AU - Nicoul, Matthieu
AU - Trigo, Mariano
AU - Andreasson, Pererik
AU - Enquist, Henrik
AU - Shu, Michael J.
AU - Pardini, Tommaso
AU - Chollet, Matthieu
AU - Zhu, Diling
AU - Lemke, Henrik
AU - Ronneberger, Ider
AU - Larsson, Jörgen
AU - Lindenberg, Aaron M.
AU - Fischer, Henry E.
AU - Hau-Riege, Stefan
AU - Reis, David A.
AU - Mazzarello, Riccardo
AU - Wuttig, Matthias
AU - Sokolowski-Tinten, Klaus
PY - 2019
Y1 - 2019
N2 - In phase-change memory devices, a material is cycled between glassy and crystalline states. The highly temperature-dependent kinetics of its crystallization process enables application in memory technology, but the transition has not been resolved on an atomic scale. Using femtosecond x-ray diffraction and ab initio computer simulations, we determined the time-dependent pair-correlation function of phase-change materials throughout the melt-quenching and crystallization process. We found a liquid–liquid phase transition in the phase-change materials Ag4In3Sb67Te26 and Ge15Sb85 at 660 and 610 kelvin, respectively. The transition is predominantly caused by the onset of Peierls distortions, the amplitude of which correlates with an increase of the apparent activation energy of diffusivity. This reveals a relationship between atomic structure and kinetics, enabling a systematic optimization of the memory-switching kinetics.
AB - In phase-change memory devices, a material is cycled between glassy and crystalline states. The highly temperature-dependent kinetics of its crystallization process enables application in memory technology, but the transition has not been resolved on an atomic scale. Using femtosecond x-ray diffraction and ab initio computer simulations, we determined the time-dependent pair-correlation function of phase-change materials throughout the melt-quenching and crystallization process. We found a liquid–liquid phase transition in the phase-change materials Ag4In3Sb67Te26 and Ge15Sb85 at 660 and 610 kelvin, respectively. The transition is predominantly caused by the onset of Peierls distortions, the amplitude of which correlates with an increase of the apparent activation energy of diffusivity. This reveals a relationship between atomic structure and kinetics, enabling a systematic optimization of the memory-switching kinetics.
UR - http://www.scopus.com/inward/record.url?scp=85067625790&partnerID=8YFLogxK
U2 - 10.1126/science.aaw1773
DO - 10.1126/science.aaw1773
M3 - Article
C2 - 31197008
AN - SCOPUS:85067625790
VL - 364
SP - 1062
EP - 1067
JO - Science (New York, N.Y.)
JF - Science (New York, N.Y.)
SN - 1095-9203
IS - 6445
ER -