Effects of charge compensation by Na+ co-doping for Ce3+ doped LiCaAlF6 single crystals

We have investigated physical properties of Na
⁺
, Ce
³⁺
co-doped LiCaAlF
₆
[Na, Ce:LiCAF] single crystals grown by micro-pulling-down method. In their X-ray diffraction measurements, grown crystals except for Ce 2%, Na 2%:LiCAF indicated a second phase of CeF
₃
. Lattice parameters of LiCAF phase systematically increased with an increase of Na and Ce concentrations. Transmittance of Na co-doped Ce:LiCAF crystals was lower than Ce:LiCAF crystal due to the inclusion of CeF
₃
in the crystals and emission peaks originated from 5d-4f transition of Ce
³⁺
ion around 285 and 310 nm were observed in all crystals. The light yield became smaller with an increase of Na concentration.