Tb3+ ions were incorporated in P Si matrix material through a sol gel process. Luminescence properties of Tb3+as a function of dopant, firing temperature, composition and structure of matrices were investigated. The g...
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Tb3+ ions were incorporated in P Si matrix material through a sol gel process. Luminescence properties of Tb3+as a function of dopant, firing temperature, composition and structure of matrices were investigated. The gels synthesized by the reaction of P2O5 or H3PO4 with tetraethoxy silane and TbCl3 as dopant were fired in air from the temperature 25～1000℃to form P Si crystalline phase. The crystal structure was determined by powder X ray diffraction. Si5O（PO4）6 were the only crystalline phase and belong to hexagonal crystal system. The emission of 5D4 7F5（～545nm） transition of Tb3+in the P Si system iscomposed of two peaks. The amount of doping Tb3+varied from 0.664%to 1.644%, and no obvious concentration quenching was observed in this doping concentration range. The intensity of Tb3+emission increased with firing temperatureincreasing and becomes stable at 800～1000℃.
A new method to prepare functional polymeric materials was *** materials were manufactured by using supramolecular blocks other than *** supramolecular block,which is an assembly of many same kinds of molecules or dif...
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A new method to prepare functional polymeric materials was *** materials were manufactured by using supramolecular blocks other than *** supramolecular block,which is an assembly of many same kinds of molecules or different kinds of molecules and particles,can show unique properties different from its original molecule or *** an example,a supramolecular luminescent block was prepared by assembly of organic luminescent molecules of (4-methacryloyloxy)trans-stilbenyltrimethylammonium bromide (MSTAB) with semiconductor nanoparticles of *** nanoparticle is as a core and MSTAB as *** block showed a very high increase in photoluminescence intensity of CdSe nanoparticles.A composite material with unique optical properties and good compatibility of two different kinds of phases was obtained by “polymerization" of the blocks.
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...
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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
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