Structural evidence for a past-ion transition in the high-pressure rocksalt phase of silver iodide
Structural evidence for a past-ion transition in the high-pressure rocksalt phase of silver iodide
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DOI：
10.1103/physrevlett.77.4914
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发表时间：
1996-12-09
影响因子：
8.6
通讯作者：
Gardner, NJG
中科院分区：
文献类型：
--
作者：
Keen, DA;Hull, S;Gardner, NJG
这封信描述了碘化银岩盐结构相在高压和高温下的中子衍射测量，以及伴随其高电导率的结构无序。在一阶结构相变，导致在环境压力下的快离子的α-碘化银，快离子的行为在岩盐结构碘化银发生以上的扩散过渡与晶格参数的一个小的异常和不断增加的占用填隙四面体网站随着温度的升高。有大约10倍以上的缺陷，在岩盐碘化银的快离子相比同构AgBr在环境压力下，1 K以下熔化。
This Letter describes neutron diffraction measurements of the rocksalt structured phase of AgI at high pressure and temperature and the structural disorder which accompanies its high conductivity. In contrast to the first-order structural phase transition which results in fast-ionic alpha-AgI at ambient pressure, the fast-ionic behavior in rocksalt structured AgI occurs above a diffuse transition with a small anomaly in lattice parameter and a continuous increase in occupation of interstitial tetrahedral sites with increasing temperature. There are approximately 10 times more defects in the fast-ionic phase of rocksalt AgI than in isostructural AgBr at ambient pressure, 1 K below melting.