Structural investigation of Ag2S+B2S3+GeS2 glasses using neutron diffraction
Structural investigation of Ag2S+B2S3+GeS2 glasses using neutron diffraction
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使用中子衍射研究 Ag2S B2S3 GeS2 玻璃的结构
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Steve W. Martin
中科院分区：
文献类型：
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作者：
Q. Mei;Steve W. Martin
用中子衍射方法研究了xAg 2S+（1-x）[B 2S 3 +GeS 2 ]（x=0.4，0.5）快离子导电玻璃的短、中程有序结构.这些玻璃由于观察到它们在其离子电导率中表现出非阿克里乌斯行为而引起重大兴趣。用高斯函数拟合了总相关函数T（r），并由Ge-S、Ag-S相关性确定了键长和配位数。在较长的长度尺度，3.1 A，一个强的相关性是轻微的温度依赖性是一致的贡献从B-B，S-S和Ag-Ag对相关性。将该相关性与晶体Ag 6 B 1 0 S 1 8中类似距离处的类似相关性进行比较，证实了虽然B-B和S-S贡献是重要的，但不能排除略微依赖于温度的Ag-Ag相关性的贡献。这一发现表明，银离子倾向于通过更扭曲的网站在较高的温度下，由于其较低的活化能传输。在3.1A处存在显著的Ag-Ag相关性，表明在室温或更高温度下，Ag离子相互作用是一个不可忽视的因素。一个可能的结果是，在升高的温度下，导电通路变得拥挤，这可以部分解释在这些玻璃中的离子电导率中看到的非阿克里乌斯行为的起源。
Fast ion conducting glasses of composition xAg 2 S+ (1-x)[B 2 S 3 +GeS 2 ] (x=0.4, 0.5) have been studied using neutron diffraction to investigate their short and intermediate range order structures. These glasses are of significant interest due to the observation that they exhibit non-Arrhenius behaviour in their ionic conductivity. The total correlation functionsT(r) were fitted with Gaussian functions and the bond lengths and coordination numbers from the Ge-S, Ag-S correlations were determined. A strong correlation at longer lengths scales, 3.1 A, is slightly temperature dependent is consistent with contributions from both B-B, S-S and Ag-Ag pair correlations. Comparison of this correlation to a similar correlation at a similar distance in the crystal Ag 6 B 1 0 S 1 8 confirms that while B-B and S-S contributions are important, the contribution of a slightly temperature dependent Ag-Ag correlation cannot be ruled out. This finding suggests that the Ag ions tend to transport through more distorted sites at higher temperatures due to their lower activation energies. The existence of significant Ag-Ag correlation at 3.1 A suggests that Ag ion interaction is a factor that cannot be ignored at room temperature or above. A possible result of this is that the conduction pathways become congested at elevated temperatures and this could partially explain the origin of the non-Arrhenius behaviour that is seen in the ionic conductivity in these glasses.