摘要
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
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 too
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第2期335-336,共2页
Chemical Journal of Chinese Universities
基金
国家重点基础研究发展规划项目 (批准号 :G19980 6 130 7)
国家自然科学基金 (批准号 :5 0 2 0 30 0 1
2 990 10 0 2
2 96 710 0 2
39730 16 0
2 0 0 2 30 0 5
5 97330 6 0
5 98730 30
5 995 30 0 1
5 990 30 0 8)
中国科学院知识创新工程 (批准号:KJCX1-Y-0 3)
