The diffusive motion of silver ions in α-AgI: Results from quasielastic neutron scattering
The diffusive motion of silver ions in α-AgI: Results from quasielastic neutron scattering
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银离子在 α-AgI 中的扩散运动：准弹性中子散射的结果
DOI：
10.1016/0022-3697(76)90137-2
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发表时间：
1976
影响因子：
4
通讯作者：
R. Lechner
中科院分区：
文献类型：
--
作者：
G. Eckold;K. Funke;J. Kalus;R. Lechner
用准弹性冷中子散射研究了250℃下银离子在σ-AgI中的扩散运动。对于弹性散射，光谱是在波矢传输0.5Q<；2.2ä−1的范围内获得的。准弹性线形包括窄分量和宽分量。它们与允许在两个不同时间尺度上叠加两种运动的模型计算相比较，局部随机运动和跳跃扩散类型的平移运动。该模型与数据非常吻合。局部随机运动发生在10−12s量级的时间尺度上，振幅在1？量级。这可能是由于其他阳离子的扩散运动引起的局部电势的快速波动所致。平移运动导致银离子在晶格常数(5？)量级的距离上的平均位移，关联时间约为10−11s。该关联时间由驻留时间和飞行时间组成，两者具有相当的量级。
The diffusive motion of silver ions in σ-AgI at 250°C has been studied by quasielastic cold neutron scattering. Spectra were taken in the range of wavevector transfer 0.5 <Q< 2.2Å−1for elastic scattering. The quasielastic line shapes contain a narrow and a broad component. They are compared to model calculations allowing for the superposition of two kinds of motion on two different time scales, a local random motion and a translational motion of the jump-diffusion type. The model closely fits the data. The local random motion takes place on a time scale of the order of 10−12s, with amplitudes of the order of 1 Å. It is probably caused by rapid fluctuations of the local potentials due to the diffusive motion of the other cations. The translational motion results in a mean displacement of the silver ion over a distance of the order of a lattice constant (5 Å) with a correlation time of the order of 10−11s. This correlation time is composed of a residence time and a time-of-flight, which are both of comparable magnitude.