Strong electronic Raman bands corresponding to the transition between 4I 9/2 and 4I 11/2 manifolds of Nd 3+ are observed in the FT-Raman spectrum of neodymium complex because of the Raman enhancement effect. Neither r...
详细信息
Strong electronic Raman bands corresponding to the transition between 4I 9/2 and 4I 11/2 manifolds of Nd 3+ are observed in the FT-Raman spectrum of neodymium complex because of the Raman enhancement effect. Neither resonant enhancement nor surface enhancement accounts for the Raman enhancement observed here. We propose a new mechanism of Raman enhancement(Feed-bach Raman Enhancement): the YAG laser excites the final state of Raman transition ( 4I 11/2 of Nd 3+) to the 4F 3/2 state and causes a significant decrease of the population of Nd 3+ at the 4I 11/2 state. This renders the population ratio of Nd 3+ at 4I 9/2 and 4I 11/2 deviates from the value required by the Boltzmann′s law. To restore equilibrium, Raman scattering is enhanced so that more Nd 3+ ions are brought from 4I 9/2 to 4I 11/2. This hypothesis gets support from the temperature-variable FT-Raman spectroscopic results. Additionally, obvious differences between Stokes and Anti-stokes Raman spectrum of Nd 3+ support our mechanism
The interaction between electrolytes and nano-Ag particles were investigated by using UV-Vis spectroscopic method. Tetramethylammonium ion, which can be hardly adsorbed on nano-Ag because of its bulky methyl group, wa...
详细信息
The interaction between electrolytes and nano-Ag particles were investigated by using UV-Vis spectroscopic method. Tetramethylammonium ion, which can be hardly adsorbed on nano-Ag because of its bulky methyl group, was used as the cation to study the variation of surface plasma resonance band of nano-Ag induced by various anions. No significant change of the band for nano-Ag could be observed when Cl - and Br - ions were introduced into nano-Ag sol. Based on the above results, different metal salts with Cl - as anion were used for investigating the spectra of nano-Ag. The nano-Ag sol exhibits a different spectral behavior when various metal ions were introduced.
A novel multiplayer film was assembled from poly[(4 carboxyphenyl)acetylene](PCPA) and diazoresin(DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of diazonium gr...
详细信息
A novel multiplayer film was assembled from poly[(4 carboxyphenyl)acetylene](PCPA) and diazoresin(DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of diazonium group between the adjacent interfaces of the multiplayers, the ionic bonds of the self assembly film convert to covalent bonds and the film becomes very stable toward electrolyte solutions. Thus the photoelectric conversion property of poly[(4 carboxyphenyl)acetylene] containing film can be measured in conventional three electrode photoelectrochemical cell, and 0.5 mol/L KCl solution can be used as the supporting electrolyte. The photocurrent spectroscopy responses coincide with the absorption spectrum of the irradiated self assembly film, which indicates that the irradiated DR/PCPA film is responsible for the photocurrent generation.
暂无评论