Hughes-Currie Rosa B, Ivanovskikh Konstantin V, Wells Jon-Paul R, Reid Michael F, Gordon Robert A, Seijo Luis, Barandiarán Zoila
Department of Physics and Astronomy, University of Canterbury , PB 4800, Christchurch 8140, New Zealand.
Institute of Physics and Technology, Ural Federal University , 620002 Ekaterinburg, Russia.
J Phys Chem Lett. 2017 Mar 16;8(6):1175-1178. doi: 10.1021/acs.jpclett.7b00262. Epub 2017 Feb 27.
Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d-f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF:Yb and SrF:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF host but not in the SrF host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb/Yb intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF excited by VUV radiation.
在电离辐射激发后发光的材料广泛应用于物理、医学、安全和工业领域。已知镧系掺杂剂通过其快速的d-f发射触发晶体闪烁；对于其他重要应用，如激光或照明用磷光体，情况也是如此。然而，这种能力可能会因最常见的镧系激活剂中经常出现的 unwanted 异常发射而受到严重损害。我们报告了在8949 eV和80 K下激发的CaF:Yb和SrF:Yb样品的高分辨率X射线激发光学（红外到紫外）发光光谱。电离辐射激发了CaF基质中已知的镱异常发射，但在SrF基质中未激发。基于波函数的从头算计算，即从主体到掺杂剂的电子转移和Yb/Yb 价间电荷转移，解释了这种差异。该模型还解释了在VUV辐射激发的Yb掺杂SrF中缺乏异常发射的原因。
