Characteristics of phase transition and separation in a In-Ge-Sb-Te system

► InGeSbTe films were fabricated via co-deposition stoichiometric GST and IST targets. ► As the amount of IST was increased in InGeSbTe, the value for Vth and the phase transition temperature were increased. ► The phase separation in InGeSbTe is caused by differences in the enthalpy change for formation and different atomic concentrations.