Structural, electronic and kinetic properties of the phase-change material Ge2Sb2Te5 in the liquid state.
Phase-change materials exhibit fast and reversible transitions between an amorphous and a crystalline state at high temperature. The two states display resistivity contrast, which is exploited in phase-change memory devices. The technologically most important family of phase-change materials consists of Ge-Sb-Te alloys. In this work, we investigate the structural, electronic and kinetic properties of liquid Ge2Sb2Te5 as a function of temperature by a combined experimental and computational approach. Understanding the properties of this phase is important to clarify the amorphization and crystallization processes. We show that the structural properties of the models obtained from ab initio and reverse Monte Carlo simulations are in good agreement with neutron and X-ray diffraction experiments. We extract the kinetic coefficients from the molecular dynamics trajectories and determine the activation energy for viscosity. The obtained value is shown to be fully compatible with our viscosity measurements.
Institute for Theoretical Solid State Physics, RWTH Aachen University, 52056 Aachen, Germany.
Mathias
M
Schumacher
IFW Dresden, Institute for Complex Materials, PO Box 270116, 01171 Dresden, Germany.|TU Dresden, Institut für Strukturphysik, 01062 Dresden, Germany.
Hans
H
Weber
Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, PO Box 49, 1525 Budapest, Hungary.
Pál
P
Jóvári
Department of Physics, Faculty of Science, Niigata University, Ikarashi 2-8050, Niigata 950-21, Japan.
Yoshimi
Y
Tsuchiya
ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, UK.
Tristan G A
TG
Youngs
IFW Dresden, Institute for Complex Materials, PO Box 270116, 01171 Dresden, Germany.
Ivan
I
Kaban
Institute for Theoretical Solid State Physics, RWTH Aachen University, 52056 Aachen, Germany.|JARA-FIT and JARA-HPC, RWTH Aachen University, 52056 Aachen, Germany.
Riccardo
R
Mazzarello