Single crystal growth, optical absorption and luminescence properties under VUV-UV synchrotron excitation of type III Ce$^{3+}$:KGd(PO$_3$)$_4$, a promising scintillator material
Résumé
Scintillator materials have gained great interest for many applications, among which the medical applications stand out. Nowadays, the research is focused on finding new scintillator materials with properties that suit the needs of each application. In particular, for medical diagnosis a fast and intense response under high-energy radiation excitation is of great importance. Here, type III Ce$^{3+}$:KGd(PO$_3$)$_4$ single crystals with high crystalline quality are grown and optically characterized as a new promising scintillator material. The $4f→5d$ electronic transitions of Ce$^{3+}$ are identified by optical absorption. The optical absorption cross section of Ce$^{3+}$ for the electronic transition from the $^2$F$_{5/2}$ to the $5d_1$ level is 370 × 10$^{−20}$ cm$^2$. The luminescence of KGd$_{0.996}$ Ce$_{0.004}$ (PO$_3$)$_4$ crystal by exciting the $5d$ levels of Ce$^{3+}$ with VUV-UV synchrotron radiation shows down-shifting properties with strong emissions at 322 and 342 nm from the $5d_1$ to $^2$F$_{5/2}$ and $^2$F$_{7/2}$ levels of Ce$^{3+}$ with a short decay time of ~16 ns, which is very suitable for scintillator applications. Moreover, these intense emissions are also observed when Gd$^{3+}$ is excited since an energy transfer from Gd$^{3+}$ to Ce$^{3+}$ exists.
Domaines
Physique [physics]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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