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Intrinsic emission of complex oxides with garnet structure was studied by means of the analyses of the time-resolved luminescence spectra and decay kinetic for single crystals (SC) and single-crystalline films (SCF) of Y 3 Al 5 O 12 (YAG) and Lu 3 Al 5 O 12 (LuAG) garnets under excitation by the pulse X-ray and synchrotron radiation at 8 -300 K. YAG and LuAG SC and SCF are characterized by significantly different concentration of the Y Al and Lu Al antisite defects (AD) due to the substantial difference in the conditions of their crystallization. For this reason, LuAG and YAG SC and SCF are very useful model objects for the study of nature of the intrinsic emission of these oxides, consisting of the excitons and AD luminescence.

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The luminescence properties of CaF2 nanoparticles with various sizes (20–140 nm) are studied upon the excitation by VUV and x-ray quanta in order to reveal the influence of ratio of mean free path and thermalization length of charge carriers and nanoparticle size on the self-trapped exciton luminescence. The luminescence intensity for exciting quantum energies corresponding to optical creation of exciton and to the range of electronic excitation multiplication is not so sensitive to nanoparticle size as for quanta with energy of Eg < hν < 2Eg. The dependences of luminescence intensity on nanoparticle size at the excitation by quanta of various energies are discussed in terms of electron-phonon and electron-electron scattering lengths and energy losses on surface defects.

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