4f7 -4f7 emission from Eu2+ in the system MF2 · AlF3

Luminescence of LiBaF3 and KMgF3 doped with Eu2+

“…In some crystals the emission consists of sharp lines related to parity forbidden intraconfigurational 4f 7 -4f 7 ( 6 P 7/2 → 8 S 7/2 ) transitions. In other materials, where the lowest state of the excited electronic configuration 4f 6 5d has lower energy than the 6 P 7/2 state, a broad band luminescence related to parity allowed 4f 6 5d → 8 S 7/2 is observed [8].…”

One step synthesis of complex fluoride powders for solid-state lasers

“…The reversible transition from beta-to gammaBaAlF 5 occurs at 789 • C. Bail et al [34] refined structure of beta and gamma phases. A delta modification was described more recently [35] f-f, line emission of Eu 2+ had been reported for this host [36].…”

Blue light emission from Eu2+ ions in sol–gel-derived Al2O3–SiO2 glasses

“…Fig. 3 shows the emission spectra of the 1Al 2 glasses doped with 1 wt% Eu 2 O 3 heated at various temperatures in 20% H 2 -80% N 2 gas atmosphere. The broad emission band peaking at around 440 nm is assigned to the 4f 6 5d-4f 7 ( 8 S 7/2 ) transition of the Eu 2+ ions.…”

“…Some rare-earth ions such as Eu, Sm and Yb can be presented as divalent ions in some hosts [1][2][3][4]. Among them, the Eu 2+ ions have attracted significant attention because of their large energy separation between the 4f 7 and 4f 6 5d configurations.…”