Phase stability and electronic structure of Si₂Sb ₂Te₅ phase-change material

On the basis of an ab initio computational study, the present work provide a full understanding on the atomic arrangements, phase stability as well as electronic structure of Si₂Sb₂Te₅, a newly synthesized phase-change material. The results show that Si₂Sb ₂Te₅ tends to decompose into Si₁Sb ₂Te₄ or Si₁Sb₄Te₇ or Sb₂Te₃, therefore, a nano-composite containing Si ₁Sb₂Te₄, Si₁Sb₄Te ₇ and Sb₂Te₃ may be self-generated from Si ₂Sb₂Te₅. Hence Si₂Sb ₂Te₅ based nano-composite is the real structure when Si₂Sb₂Te₅ is used in electronic memory applications. The present results agree well with the recent experimental work.