Eu+2 Emission in Ternary Alkaline Earth Aluminum Fluorides

Abstract

The ternary systems MF2‐MF2‐AlF3 where M=normalCa,normalSr,normalor Ba , were examined for compatibility triangles and compounds. The compounds SrCaAlF7 and BaCaAlF7 were found, each with three polymorphs. The β‐ and γ‐forms in the SrCaAlF7 compound could be quenched. The two low‐temperature (α) forms show strong line emission at 358 to 360 nm with Eu+2 activation, resulting from absorption into the 5d states and emission from the 6P7/2 levels to the 8S7/2 ground state. The β‐ and γ‐forms of SrCaAlF7 contain a band emission and a much weaker line.

Correlation between 19F Environment and Isotropic Chemical Shift in Barium and Calcium Fluoroaluminates

“…15 The R-phase is obtained by heating a stoichiometric mixture of BaF 2 /CaF 2 /AlF 3 at 750 °C for 2 days followed by natural cooling. 25 2. 19 F NMR.…”

Two-photon excitation spectra of divalent europium in cubic perovskiteKMgF3

“…The 6 P 7/2,5/2 levels were observed in the one-photon spectrum of Eu 2ϩ in KMgF 3 , 6-8 alkaline-earth sulfates, 9 and ternary alkalineearth aluminum fluorides. 10 In these crystals 6 P 7/2,5/2 states occur below the onset of the 4f 6 5d absorption band edge, and can be seen in absorption and emission as narrow lines corresponding to the transitions 8 S 7/2 → 6 P 7/2,5/2 . Emission and one-photon excitation to the 6 I levels of Eu 2ϩ in KMgF 3 have also been observed.…”

Huge enhancement of Sm2+ emission via Eu2+ energy transfer in a SrB4O7 pressure sensor

“…the characteristic 4f 6 5d -4f 7 transition of Eu 2+ centered at 367 nm (broad band) and the rarely observed 4f 7 -4f 7 line-type (narrow) transitions of Eu 2+ centered at E362.1 and E362.7 nm. [58][59][60][61] On the other hand, the red emissions of Sm 2+ , located in the range of E680-750 nm, correspond to 5 D 0 -7 F 0 (685.4 nm), 5 D 0 -7 F 1 (695.4, 698.6, 704.6 nm), 5 D 0 -7 F 2 (722.1, 724.2, 727.0 and 733.5 nm) and they are associated with 4f 6 -4f 6 intra-configurational transitions of Sm 2+ ions. It is clearly seen that the 5 D 0 -7 F 0 transition of Sm 2+ exhibits its characteristic isolated, narrow and intense singlet band located at 685.4 nm.…”