Pressure-induced structural transitions in phase-change materials based on Ge-free Sb-Te alloys

We report on pressure-induced phase transitions in the Sb(2)Te and Ag(11)In(6)Sb(55)Te(28) (AIST) phase change alloys used in optical recording media over a pressure range from ambient pressure to 40 GPa. The results clearly demonstrate the crucial role of dopants in sequences of high-pressure structural transformations and in the degree of reversion. We also demonstrate that prolonged exposure of AIST to high pressures leads to an additional phase transition that may have fatal consequences for process reversibility in repeated compression/decompression cycles.