GdB3O6中Gd3+的级联发射特性

报道了Gd³⁺离子在GdB₃O₆基质中的光子级联发射特性。用Hitachi M850荧光分光光度计测定了Gd^{3+ 6}G_J能态的位置和Gd³⁺离子的光子级联发射光谱,Gd³⁺离子的第一个光子发射为⁶G_J→⁶P_J(～600nm)和⁶G_J→⁶I_J(～780nm),第二个光子的发射为⁶P_J→⁸S_7/2(～310nm)。由于⁶D_9/2与⁶I_11/2间能级差(～2900cm^-1)和⁶I_7/2与⁶P_J间能级差(～3900cm^-1)较小,多声子弛豫的几率明显超过辐射跃迁几率。因此,当用⁸S_7/2→⁶G_J(202nm)的紫外光激发时,只能观察到⁶P_J→⁸S_7/2(～310nm)、⁶G_J→⁶P_J(～600nm)和⁶G_J→⁶I_J(～780nm)的发射跃迁,未能观察到⁶I_J→⁸S_7/2(～275nm)和⁶D_J→⁸S_7/2(～250nm)的发射跃迁。

Photo Cascade Emission of Gd3+ in GdB3O6

GdB₃O₆ was synthesized by the solid state reaction at high temperatures.The UV excitation and emission spectra were recorded by a Hitachi M850 fluorescent spectrometer at room temperature.Because the part of ⁶G_J energy levels of Gd³⁺ are below 50000cm^-1,so these ⁶G_J energy levels of Gd³⁺ could be measured by UV excitation.The observation of photon cascade emission of the Gd³⁺ ion in GdB₃O₆ under ⁸S_7/2^→6G_J ultraviolet excitation(202nm) was reported.In this host lattice,the lowest energy state of the Gd³⁺ 4f5d excited configuration is located above the ⁶G_J state.The ⁶G_J^→6P_J and ⁶G_J^→6I_J transitions are responsible for the first photon emission.The second photon emission originates from the ⁶P_J^→8S_7/2 transitions.In the GdB₃O₆ host,the energy difference ΔE between the⁶D_9/2 and ⁶I_11/2(about 2900cm^-1),and that between ⁶I_7/2 and ⁶P_J(about 3900cm^-1) are smaller,the multiphonon relaxation rate exceeds remarkably the radiative decay rate,so the absence of emission from the ⁶D_J and ⁶I_J states to the ground state ⁸S_7/2 is attributed to the efficient multiphonon ⁶D_J^→6I_J and ⁶I_J^→6P_J relaxation.