Insight into the role of nitrogen in the phase-change material Sb

The influence of nitrogen dopant on the structure of the phase-change material Sb has been investigated by ab initio molecular dynamics simulations. The doped N exist as SbN complex in amorphous phase and would not enter into the rhombohedra phase of crystalline Sb. During crystallization of the amorphous phase, no N2 molecule is formed and part of the N–Sb bonds are broken to release Sb atoms which contribute to growth of crystal nuclei by forming more Sb–Sb bonds. Remaining N–Sb bonds would segregate at the grain boundaries and retard growth of crystal nuclei.