Nature of the Alkali Surface Bond at Low Coverages Investigated by Vibrational Measurements
Nature of the Alkali Surface Bond at Low Coverages Investigated by Vibrational Measurements
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通过振动测量研究低覆盖率碱表面键合的性质
DOI：
10.1021/jp800305x
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发表时间：
2008
影响因子：
3.7
通讯作者：
G. Chiarello
中科院分区：
文献类型：
--
作者：
A. Politano;R. Agostino;E. Colavita;V. Formoso;L. Tenuta;G. Chiarello
高分辨率电子能量损失谱已被用于研究Na/Ni（111）和K/Ni（111）键在极低覆盖率下的性质。对非常干净的碱层进行的测量首次提供了碱-基底拉伸能量作为碱覆盖的函数的预期行为。此外，我们发现共吸附的CO分子对Na - Ni （K - Ni）键产生了显著的影响，导致Na - Ni （K - Ni）振动频率发生红移。我们认为，这种影响可能是基于计算和测量的振动能量作为碱覆盖的函数之间存在的差异。
High-resolution electron energy loss spectroscopy has been used to study the nature of the Na/Ni(111) and K/Ni(111) bond at very low coverages. Measurements taken for very clean alkali layers provided, for the first time, the expected behavior of the alkali−substrate stretching energy as a function of the alkali coverage. Moreover, we found that the Na−Ni (K−Ni) bond was dramatically influenced by coadsorbed CO molecules causing a red shift of the Na−Ni (K−Ni) vibrational frequency. We argue that this effect could be at the base of discrepancies existing between the calculated and measured behavior of the vibrational energies as a function of the alkali coverage.