ABSTRACT AgI can transform a face-centred cubic lattice structure under pressures in the range 0.4–11.3 GPa. These phases also exhibit high ionic conductivities, particularly at high temperatures. The full-potential linear muffin-tin-orbital (FP-LMTO) method is used to investigate the ion conduction mechanisms of AgI under high pressures, wherein the exchange correlation energies of electrons are calculated via both local density approximation and generalised gradient approximation and then compared. The total energy calculations exhibit saddle points along the migration pathways, where Frenkel defects should be stable. Our results suggest that Frenkel defects do not easily migrate from stable positions, particularly under high pressures. This implies that Frenkel defects dominate ionic conduction not only in AgCl and AgBr, but also in rocksalt-structured AgI.

中文翻译：

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高压下卤化银的离子传导机制

摘要 AgI 可以在 0.4-11.3 GPa 范围内的压力下转变面心立方晶格结构。这些相还表现出高离子电导率，特别是在高温下。全电位线性松饼锡轨道 (FP-LMTO) 方法用于研究高压下 AgI 的离子传导机制，其中通过局部密度近似和广义梯度近似计算电子的交换相关能，然后比较的。总能量计算显示出沿迁移路径的鞍点，其中 Frenkel 缺陷应该是稳定的。我们的结果表明 Frenkel 缺陷不容易从稳定位置迁移，特别是在高压下。这意味着弗伦克尔缺陷不仅在 AgCl 和 AgBr 中主导离子传导，