Study of glass-forming ability and structural rigidity of Zn-modified (GeTe)x(Sb2Te3)100−x chalcogenide glassy alloys

Abstract

ABSTRACTTelluride-based phase-change chalcogenide alloys have utmost importance in memory applications due to their ultrafast switching between amorphous to microcrystalline and vice versa. The present study reports the compositional-dependent physical parameters of Zn modified (GeTe)x(Sb2Te3)100−x chalcogenide phase-change alloys to explicate their glass-forming ability and memory switching properties in terms of expected presence of chemical bonds. The theoretical estimation of physical properties of GeTe, Ge8Sb2Te11, Ge2Sb2Te5 and Sb2Te3 phase-change chalcogenide alloys and comparison of effects of Zn doping in the alloys have been carried out. These include average coordination number, number of lone pair electrons, deviation of stoichiometry, electronegativity and overall mean bond energy. The glass transition temperature of Zn-modified (GeTe)x(Sb2Te3)100−x alloys has been estimated by the model presented by Lankhorst and cohesive energy (CE) of the systems is calculated using chemical bond approach model. A linear relation is found between CE and the heat of atomization for all compositions.