Origin of radiation tolerance in amorphous Ge 2 Sb 2 Te 5 phase-change random-access memory material

Significance Radiation-hard nonvolatile memories are in high demand by the space community for implementation in solid-state data recorders. In phase-change memories, binary data are represented as changes in structural phase rather than by stored electrical charge; thus, these devices are supposed to be tolerant to ionizing radiation effects. In addition, they feature high cycling capability and large scaling potential. We present ab initio calculations of radiation damage in amorphous phase-change materials. The glass shows a recovery from the damage imposed during ion irradiation, as it manages to maintain its amorphous network. Our simulations manifest the remarkable ability of Ge2 Sb2 Te5 phase-change random-access memory material to be radiation-tolerant, hence indicating its potential applications in future space and other radiation-present environments.