Phase change materials can be reversibly switched between amorphous and
crystalline states and often show strong contrast in the optical and electrical
properties of these two phases. They are now in widespread use for optical data
storage, and their fast switching and a pronounced change of resistivity upon
crystallization are also very attractive for nonvolatile electronic data
storage. Nevertheless there are still several open questions regarding the
electronic states and charge transport in these compounds. In this work we
study electrical transport in thin metallic films of the disordered,
crystalline phase change material Ge1​Sb2​Te4​. We observe weak
antilocalization and disorder enhanced Coulomb interaction effects at low
temperatures, and separate the contributions of these two phenomena to the
temperature dependence of the resistivity, Hall effect, and magnetoresistance.
Strong spin-orbit scattering causes positive magnetoresistance at all
temperatures, and a careful analysis of the low-field magnetoresistance allows
us to extract the temperature dependent electron dephasing rate and study other
scattering phenomena. We find electron dephasing due to inelastic
electron-phonon scattering at higher temperatures, electron-electron scattering
dephasing at intermediate temperatures, and a crossover to weak temperature
dependence below 1 K