Luminescence of F+ and F centers in YAlO3

In YAlO3 crystals grown in vacuum or reduced by annealing at low oxygen pressure, the luminescence of F centers in the band at 420 nm, with tau = 30 ms at 9 K, excited in the bands at 212 and 242 nm, as well as the luminescence of F+ centers in the band at 355 nm, with tau = 2.7 ns, excited in the main band at 220 nm and weaker bands at 190 and 288 nm, was detected. On the basis of the results obtained and data in the literature, the behavior of the emission of F+ and F centers in oxides of the Al2O3-Y2O3 system is analyzed on the example of the compounds alpha-Al2O3, YAlO3, and Y3Al5O12. The role of antisite defects in the stabilization of F-like luminescence and absorption centers in multisublattice oxides is discussed. (C) 2004 MAIK Nauka/Interperiodica.