Excitation energy transfer in Ce[F.sub.3] single crystals doped with [Sr.sup.2+]

Ce[F.sub.3] single crystals heavily doped with [Sr.sup.2+] ions are grown by the micro-pulling-down ([mu]-PD) method. The deviation of the composition in as-grown crystals is found to be entirely negligible. Three dimensional emission-excitation spectra are measured in a wide temperature range of 5-300 K by using synchrotron radiation as an exciting light source. Two intense emission bands are observed at around 320 and 400 nm. The origin of these bands is discussed on the basis of the perturbation effects introduced by Sr doping. It is pointed out that the energy transfer takes place from [Ce.sup.3+] sites to defect sites when the crystal is warmed from 5 to 300 K. Index Terms--Crystal growth, energy conversion, fluorine compounds, luminescence, rare earth metals.