Masalov A. Feature of spectra formation and relaxation channels of electronic excitation energy of the activation centers in bulk and nanoscale crystals Re2SiO5:Pr3+, Ce3+ (Re=Y, Lu)

The objects are Y2SiO5:Pr3+, Lu2SiO5:Pr3+, Lu2SiO5:Се3+ crystals and nanocrystals. Aim: to define feature of spectra formation and relaxation channels of electronic excitation energy of the activation centers in bulk and nanoscale crystals Re2SiO5:Pr3+, Ce3+ (Re=Y, Lu). The methods are laser spectroscopy with time and space resolution, single molecular technique. Results, novelty: it has been shown that in Y2SiO5:Pr3+ nanocrystal speed of nonradiactive relaxations on crystal-field components D term of ion Pr strongly supressed; Two mechanisms of fluorescence quenching of the activator in Y2SiO5:Pr3+ are established: (1) forster mechanism between the nonequivalent optical canters, (2) mechanism of a cooperative cross-relaxation in a subsystem of the same optical canters. The fields of implementation are active laser media for diode pumping, effective, fast-acting scintillators for positron tomographs and high energy physics.