Rewritable optical storage is dominated by alloys of a small number of elements, particularly Ge, Sb, and Te, and Ge/Sb/Te alloys in the composition range (GeTe)(SbTe) (0 ≤ ≤ 1) have been the materials of choice: all have metastable rock salt structures that change little over decades at archival temperatures, and all contain vacancies (cavities). The special status arises from the close similarity of the valence orbitals of Ge, Sb, and Te, which arises from the irregular changes in atomic orbitals and properties as the atomic number increases (“secondary periodicity”). The instability of cubic (metallic) Bi to a (semimetallic) rhombohedral structure (H. Jones, 1934) can be adapted to Ge/Sb/Te alloys and explains the crucial metastable (rock salt) structures of these compounds. Vacancies almost always occur next to Te atoms, which form one sublattice of the rock salt structure.

中文翻译：

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相变存储材料：为什么 Ge、Sb 和 Te 合金是首选材料？

可重写光存储以少量元素的合金为主，特别是Ge、Sb和Te，成分范围(GeTe)(SbTe)(0≤≤1)的Ge/Sb/Te合金已成为可重写光存储的材料。选择：所有这些都具有亚稳态岩盐结构，在档案温度下几十年来几乎没有变化，并且都含有空位（空腔）。这种特殊的地位源于Ge、Sb和Te的价轨道非常相似，这是由于原子轨道和性质随着原子序数的增加而发生不规则变化（“二次周期性”）。立方（金属）Bi 到（半金属）菱面体结构的不稳定性（H. Jones，1934）可以适用于 Ge/Sb/Te 合金，并解释了这些化合物的关键亚稳态（岩盐）结构。空位几乎总是出现在Te原子旁边，Te原子形成岩盐结构的一个亚晶格。