Synthesis and structure resolution of RbLaF4.
The synthesis and  structure resolution of RbLaF(4) are described. RbLaF(4) is synthesized by  solid-state reaction between RbF and LaF(3) at 425 °C under a nonoxidizing atmosphere. Its crystal structure has been resolved by combining neutron and synchrotron powder diffraction data refinements (Pnma,a = 6.46281(2) Å, b = 3.86498(1) Å, c = 16.17629(4) Å, Z = 4). One-dimensional (87)Rb, (139)La, and (19)F MAS NMR spectra have been recorded and are in agreement with the proposed structural model. Assignment of the (19)F resonances is performed on the basis of both (19)F-(139)La J-coupling multiplet patterns observed in a heteronuclear DQ-filtered J-resolved spectrum and (19)F-(87)Rb HMQC MAS experiments. DFT calculations of both the (19)F isotropic chemical shieldings and the (87)Rb, (139)La electric field gradient tensors using the GIPAW and PAW methods implemented in the CASTEP code are in good agreement with the experimental values and support the proposed structural model. Finally, the conductivity of RbLaF(4) and  luminescence properties of Eu-doped LaRbF(4) are investigated.
CEMHTI, CNRS UPR 3079, Orléans, France. anne-laure.rollet@upmc.fr
Anne-Laure
AL
Rollet
Mathieu
M
Allix
Emmanuel
E
Veron
Michael
M
Deschamps
Valérie
V
Montouillout
Matthew R
MR
Suchomel
Emmanuelle
E
Suard
Maud
M
Barre
Manuel
M
Ocaña
Aymeric
A
Sadoc
Florent
F
Boucher
Catherine
C
Bessada
Dominique
D
Massiot
Franck
F
Fayon