The defect structure of CaF2:U3+

Synthesis and optical characterizations of undoped and rare-earth-doped CaF2 nanoparticles

“…5(a). This difference, with regard the undoped CaF 2 , is certainly due to the F À ions interstitials which lead to a dominant defect structure [26,27], especially at high doping levels. Moreover, the defects in the RE-doped CaF 2 can aggregate and form clusters [28] which should have an effect on both speed and orientation of the particles growth.…”

Nanoscale CaF2 doped with Eu3+ and Tb3+ through fluorolytic sol–gel synthesis

“…The 1 : 0 : 3-cluster (1 vacancy, 0 F 0 and 3 F 00 ) is generated through doping larger cations (La 3+ .Tb 3+ ), whereas the 8 : 12 : 1-cluster (8 vacancy, 12 F 0 and 1 F 00 ) is energetically stabilized by doping smaller cations (Ho 3+ .Lu 3+ and Y 3+ ). 11,12 In recent years rare earth-doped alkaline earth metal uorides gathered increasing attention. 2006 Feldmann reported a thermally assisted polyol-mediated precipitation synthesis of nanocrystalline CaF 2 and CaF 2 :Ce,Tb.…”

EPR results and Raman spectroscopy as a complementary characterization of isolated Yb ions and Yb pairs in CaF2:Yb single crystals

“…At low concentration (less then 1 mol%) the additional F − ion goes into a next-nearest-neighbour void of the trivalent rare-earth ion giving isolated defects. For dopant concentration larger than 1 mol%, anion clusters involving more than one dopant cation is formed [2].…”