Fast crystallization and low-power amorphization of Mg–Sb–Te reversible phase-change films

Abstract

We prepared Mg-doped Sb₂Te films and investigated their structural, optical and electrical properties. It was found that Mg doping can increase the crystallization temperature, suppress the crystal growth and shorten the crystallization time of Sb₂Te. Compared to Ge₂Sb₂Te₅, the optimal composition of Mg_21.5(Sb₂Te)_78.5 exhibited a higher crystallization temperature (~183 °C), larger crystallization activation energy (~3.86 eV), and better data retention ability (maintaining the amorphous state at ~121 °C for ten years), indicating improved amorphous state stability due to the formation of Mg–Sb bonds. A reversible, repetitive optical switching behavior was realized in the Mg_21.5(Sb₂Te)_78.5 film, with a fast crystallization speed of 52 ns and a low amorphization power of 35 mW.