Amorphous-Crystal Phase Transitions in Ge2Sb2Te5 and GexTe1-x alloys

Aim of this work was the investigation of the phase transitions in Ge2Sb2Te5 and GexTe1-x thin films. These alloys are of interest since they exhibit an excellent combination of electrical-optical and phase changing characteristics for memory applications. In particular we have focused our attention on the amorphous-crystal transition. We have then discussed the correlation between the local order in the amorphous network and the crystallization kinetics. To this aim we have modified the properties of the amorphous phase by laser and ion irradiation looking to the consequent variation in the phase transition speed.