Adell Irina, Solé Rosa Maria, Pujol Maria Cinta, Aguiló Magdalena, Díaz Francesc
Universitat Rovira i Virgili, Departament Química Física i Inorgànica, Física i Cristal·lografia de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Campus Sescelades, E-43007 Tarragona, Spain.
ACS Omega. 2018 Sep 18;3(9):11307-11316. doi: 10.1021/acsomega.8b01321. eCollection 2018 Sep 30.
Scintillator materials are used as detectors in the ray imaging techniques for medical diagnosis. Because the ideal medical scintillator material does not exist, many efforts are being made to find new materials that satisfy a greater number of properties. Here, the synthesis conditions of Pr:KGd(PO) nanocrystals by the modified Pechini method are optimized to obtain a single crystalline phase of those that form the polymorphism of KGd(PO). The interest lies in the type III phase because less quenching by Pr concentration is expected. By performing transmittance measurements and because of the wide transparency window of the type III KGd(PO) host, the H → 5d absorption transition of Pr has been observed in the vacuum ultraviolet spectral range. After creating electron-hole pairs in the host due to the excitation of the material by X-ray radiation, the bands corresponding to the 5d → H, H, H and 5d → F, F, G transitions of Pr have been observed in the near-visible spectral range, being these 5d → 4f transitions interesting for scintillation applications. Therefore, the type III Pr:KGd(PO) nanocrystals allow the conversion from high-energy radiation to visible or near-visible light.
闪烁体材料在用于医学诊断的射线成像技术中用作探测器。由于不存在理想的医用闪烁体材料，人们正在做出许多努力来寻找满足更多性能的新材料。在此，通过改进的佩琴尼法优化了Pr:KGd(PO)纳米晶体的合成条件，以获得形成KGd(PO)多晶型的单晶相。研究兴趣在于III型相，因为预计Pr浓度引起的猝灭较少。通过进行透射率测量，并且由于III型KGd(PO)基质具有宽的透明窗口，在真空紫外光谱范围内观察到了Pr的H→5d吸收跃迁。在材料被X射线辐射激发在基质中产生电子-空穴对之后，在近可见光谱范围内观察到了对应于Pr的5d→H、H、H和5d→F、F、G跃迁的能带，这些5d→4f跃迁对于闪烁应用很有意义。因此，III型Pr:KGd(PO)纳米晶体能够实现从高能辐射到可见光或近可见光的转换。
