Origin of Absorption Bands Observed in the Spectra of Silver Ion‐Exchanged Soda–Lime–Silica Glass
Origin of Absorption Bands Observed in the Spectra of Silver Ion‐Exchanged Soda–Lime–Silica Glass
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DOI：
10.1111/j.1151-2916.1995.tb08054.x
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发表时间：
1995-10
影响因子：
3.9
通讯作者：
A. Ahmed;E. A. Allah
中科院分区：
文献类型：
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作者：
A. Ahmed;E. A. Allah
测量了在不同条件下通过离子交换制备并经过不同热处理的含银钠钙硅玻璃在紫外和可见光区的光谱吸收。进行了试验性高斯分辨率分析，以准确定义实验观察到的吸收光谱的组分带。光谱数据用于识别不同条件下处理的样品中银的不同状态以及形成的银颗粒的形状和空间排列。所得数据还与已知的确定银态的特征吸收进行了比较。离子交换后玻璃的光谱在305 nm处显示出单一尖锐的对称吸收带。在热处理后，根据热处理条件，观察到在UV和可见光中的一个或两个额外的吸收带。这些谱带的行为-出现顺序、稳定性范围和强度波动，作为离子交换和热处理的温度和时间的函数-将表明以下谱带分配：·305 nm处的谱带与Ag+离子相关。·350 nm处的谱带与Ag°（元素Ag原子）相关。·420 nm处的谱带与（Ag°）n（银微晶，n是形成微晶的银原子的数目）相关。该条带分配与广泛接受的银染色过程中发生的事件顺序一致。从与银颗粒相关的单个吸收带推导出的附加信息表明，银颗粒是球形的，并且彼此隔离到防止电磁相互作用所必需的程度。
The spectral absorption of Ag-containing soda–lime–silica glasses, prepared by ion exchange under different conditions and subjected to different heat treatments, was measured in the UV and visible. Tentative Gaussian resolution analysis was performed to accurately define the component bands of the experimentally observed absorption spectra. The spectral data were used to identify the different states of silver and the shape and the spatial arrangement of the silver particles formed in the samples treated under different conditions. The data obtained were also compared with the known characteristic absorption of definite silver states. The spectra of glasses after ion exchange showed a single sharp symmetrical absorption band in the UV at 305 nm. After heat treatment, one or two additional absorption bands in the UV and visible were observed, depending on the heat-treatment conditions. The behavior of these bands—sequence of appearance, ranges of stability and intensity fluctuation, as a function of temperature and time of ion exchange and heat treatment—would suggest the following band assignment: •Band at 305 nm is associated with Ag+ ions. •Band at 350 nm is associated with Ag° (elemental Ag atoms). •Band at 420 nm is associated with (Ag°)n (silver crystallites, n is the number of silver atoms forming the crystallite). This band assignment is in conformity with the sequence of events widely accepted to take place during silver staining. Additional information deduced from the single absorption band associated with silver particles indicates that the silver particles are spherical in shape and isolated from each other to the extent necessary to prevent electromagnetic interaction.