Site Selective Spectroscopy of CaF2:Eu3+ Nanoparticles
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
Trivalent europium doped calcium fluoride nanoparticles have been investigated using laser site selective spectroscopy. In these core only particles, four distinct spectroscopic cen- tres have been observed, using excitation into the 5D0 and 5D1 multiplets of Eu3+. The sites labelled 1/1a display very similar spectroscopic properties including an absence of emission from the 5D1 multiplet. It is suggested that these centres are two related configurations of quite low symmetry, residing on or near the surface of the nanoparticle. Two further sites, labelled sites 2/2a exhibit much longer lifetimes and 5D1 emission is observed. We tentatively conclude that these are centres embedded within the nanoparticle. Site 2 shares spectroscopic features with the C2v(Na+) centres observed in bulk co-doped samples whilst site 2a appears to exhibit 17.4 ms 5D0 lifetimes which is closely similar to cubic centres in the bulk crystals.