OBSERVATION OF THE ENHANCED INFRARED-ABSORPTION OF PARA-NITROBENZOATE ON AG ISLAND FILMS WITH AN ATR TECHNIQUE
OBSERVATION OF THE ENHANCED INFRARED-ABSORPTION OF PARA-NITROBENZOATE ON AG ISLAND FILMS WITH AN ATR TECHNIQUE
复制标题
DOI：
10.1007/bf00632429
复制
发表时间：
1982-01-01
影响因子：
2.7
通讯作者：
SUETAKA, W
中科院分区：
文献类型：
--
作者：
HATTA, A;OHSHIMA, T;SUETAKA, W
通过使用ATR技术，我们发现在约5 nm厚的银岛膜上形成的对硝基苯甲酸盐的红外吸收增强了10倍左右。只有涉及垂直于宏观银表面的苯甲酸盐离子偶极矩变化的振动模式才被p偏振辐射单独增强，这表明垂直于银表面偏振的倏逝波电场在红外激发过程中起主导作用。沉积在 5 纳米厚的银底层上的单层硬脂酸给出了增强的另一个例子。尽管增强机制尚未完全阐明，但基于银岛集体电子共振的现有模型不适用于当前情况，因为它预测无论红外光束的偏振状态如何都可以激发电子共振。
By the use of an ATR technique we have found that the infrared absorption of p-nitrobenzoate, formed on Ag island film about 5 nm thick, is enhanced by a factor of the order of 10. Only vibrational modes involving a change in the dipole moment of the benzoate ion perpendicular to the macroscopic Ag surface are enhanced by p-polarized radiation alone, indicating the electric field of the evanescent wave polarized perpendicular to the Ag surface plays a dominant role in the infrared excitation process. A monolayer of stearic acid deposited on a Ag underlayer 5nm thick gave another example of the enhancement. Although the mechanism of enhancement is not fully elucidated, the existing model based on the collective electron resonances of Ag islands is not applicable to the present case, since it predicts the electron resonance can be excited irrespective of polarization state of infrared beam.