Metastable rocksalt structured Ge₂Sb₂Te₅ is the most widely used phase-change material for data storage, yet the atomic arrangements of which are still under debate. In this work, we have proposed metastable stacking-polymorphism in cubic Ge₂Sb₂Te₅ based on first-principles calculations. Our results show that cubic Ge₂Sb₂Te₅ is actually polymorphic, varying from randomly distributed vacancies to highly ordered vacancy layers; consequently, the electrical property varies between metallic and semiconducting. These different atomic stackings of cubic Ge₂Sb₂Te₅ can be obtained at different experimental synthetic conditions. The concept of stacking-polymorphic Ge₂Sb₂Te₅ provides important fundamentals for metastable Ge₂Sb₂Te₅ and is useful for tuning the performance of the phase-change materials.

中文翻译：

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Ge ₂ Sb ₂ Te _5中的亚稳态堆积多态性

亚稳岩盐结构的Ge ₂ Sb ₂ Te ₅是用于数据存储的最广泛使用的相变材料，但其原子排列方式仍在争论中。在这项工作中，我们基于第一性原理计算提出了立方Ge ₂ Sb ₂ Te _5中的亚稳态堆积多态性。我们的结果表明，立方Ge ₂ Sb ₂ Te ₅实际上是多态的，从随机分布的空位到高度有序的空位层不等。因此，电性能在金属和半导体之间变化。这些不同的立方Ge ₂ Sb ₂原子堆积Te ₅可以在不同的实验合成条件下获得。堆叠多态性Ge的概念₂的Sb ₂碲₅提供了亚稳定的Ge重要基本面₂的Sb ₂碲₅和是用于调谐所述相变材料的性能是有用的。