Cross-luminescence of several complex fluorides excited by synchrotron radiation

Time-resolved luminescence characteristics of the two groups of complex cross-luminescent (CRL) fluorides, namely, BaF2-based (BaY2F8, BaY2F8RE3+ (RE = Ce, Nd, Er, Tm, Yb)) and KF-based fluorides (KYF4, KLuF4, K2YF5, KLiYF5, KLiLuF5 and K2LiGaF6) have been investigated under pulsed synchrotron radiation excitation at 100 K and 300 K. It was found that in BaY2F8 the emission of self-trapped excitons was considerably quenched at 300 K compared with that of BaF2 and the present “slow” emission was caused by uncontrollable rare earth admixtures. In Yb3+-doped BaY2F8 this emission is strongly quenched providing good fast scintillation characteristics. The studied KF-based complex crystals show intensive CRL at 300 K with the spectrum situated mainly in the far VUV spectral range. Data on the new CRL crystals KLiYF5 and KLiLuF5 are reported.