VUV spectroscopy of BaF2:Er
VUV spectroscopy of BaF2:Er
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BaF2:Er 的 VUV 光谱
DOI：
10.1016/j.optmat.2007.09.017
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发表时间：
2009
影响因子：
3.9
通讯作者：
A. Wojtowicz
中科院分区：
文献类型：
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作者：
A. Wojtowicz
为了寻找快速、高效的真空紫外闪烁体材料，在汉堡Superlumi站测量了BaF_2：Er的紫外和真空紫外发光和发光激发光谱。虽然，在选择性真空紫外激发下，我们观察到4f 105 d-4f 11 VUV发射，它是相对缓慢的，并没有有效地激发在低于124 nm的VUV波长。在真空紫外激发光谱中观察到的结构反映了10个4f电子的重排，这些电子是通过将原始4f 11构型的4f电子之一跃迁到最低能量d轨道而留下的。其他发射带，激发在互补的真空紫外波长，是由于4f 11配置内跃迁。这些跃迁的真空紫外激发机制涉及Er ~（3+）离子的束缚激子。随后的大能量弛豫导致与Er 3+离子相关联的F-H对阻止能量转移到5d4 f10构型的更高的激发态。即使当直接达到5d4 f10组态时，产生5d4 f10组态的高自旋和低自旋（HS和LS）激发态的5d和4f 10电子之间的耦合也是BaF 2：Er中相对较慢的d-f发射的原因。综上所述，Er ~（3+）激活的BaF_2在电离激发下不能提供新的发光材料所期望的快速和有效的发光。
Luminescence and luminescence excitation spectra of BaF2:Er in UV and VUV have been measured at Superlumi station in Hamburg, in search for fast and efficient VUV scintillator materials. Although, under selective VUV excitations, we observe the 4f105d–4f11VUV emission, it is relatively slow and is not efficiently excited at VUV wavelengths below 124nm. The structure observed in the VUV excitation spectra reflects rearrangement of ten 4f electrons left behind by transition promoting one of the 4f electrons of the original 4f11configuration to the lowest energy d-orbital. Other emission bands, excited at complementary VUV wavelengths, are due to the 4f11intra-configuration transitions. The VUV excitation mechanism of these transitions involves a bound exciton at Er3+ion. Subsequent large energy relaxation leading to the F–H pair associated with the Er3+ion prevents energy transfer to the higher lying states of the 5d4f10configuration. Even when the 5d4f10configuration is reached directly, the coupling between the 5d and 4f10electrons generating the high and low spin (HS and LS) excited states of the 5d4f10configuration is responsible for relatively slow d–f emission in BaF2:Er. In summary, the Er3+activated BaF2fails to provide fast and efficient emission under ionizing excitation, expected of new scintillating materials.