Thermal properties of phase change material Ge2Sb2Te5 doped with Bi

The influence of Bi doping on the thermal properties and thermal stability of Ge2Sb2Te5 thin films was investigated. It was shown that Bi doping allows the change of thermal properties in wide range, and increase thermal stability of thin films. It was also shown that the doping of bismuth affects the electrical properties of the material. The existence of two Bi concentration ranges with two different doping mechanisms and influences on the film properties was established. In the range of low concentrations (0.5–1.0 wt.% of Bi) the anomalous deviations of properties from main tendencies were observed. This effect is explained with the use of percolation theory when at critical concentration (percolation threshold) formation of infinite cluster is accompanied by critical phenomena.