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Photostimulated luminescence phosphors are promising candidates for next‐generation optical data storage devices. Herein, optically‐reversible luminescence modulation is demonstrated using UV wavelengths in the fluoroperovskite RbCdF3:Mn, where the modulation is mediated by photostimulated luminescence processes. UV‐C stimulation enhances the luminescence from Mn2+ centers and simultaneously fills electron traps. This charging process occurs via electron transfer from Mn2+ ions to fluorine vacancies, yielding Mn3+ ions and F‐centers, and is mediated by conduction band transport. UV‐A stimulation restores the material to the initial state. This discharging process occurs via electron transfer from F‐centers to Mn3+ ions and is similarly mediated by conduction band transport. Moreover, the discharging process manifests Mn2+ photostimulated luminescence. The primary trap state has activation energies in the range 1.46 to 1.73 eV and has room temperature lifetimes exceeding 40 000 years. A kinetic model is presented and evaluated that accurately describes the charge transport and luminescence properties of the material. Thus, a material is presented via which ultra‐long term, multi‐level luminescent data storage can be realized, and a model via which precise control over the luminescence modulation and photostimulated luminescence intensities can be achieved. [ABSTRACT FROM AUTHOR]

Photoluminescence (PL), PL lifetime, and radioluminescence (RL) measurements were made on LaF3 nanoparticles doped with Eu3+ or Sm3+. The radiative lifetimes decreased with increasing rare earth concentrations, which can be attributed to energy transfer to the surface of the nanoparticles followed by non-radiative recombination. The RL signal increases with increasing concentration for Eu3+ concentrations up to 20% Eu3+ but it saturates and disappears for >10% Sm3+. A dose-independent RL was observed up to 10 kGy during continual X-ray irradiation for Eu3+ and Sm3+ doped nanoparticles, which is advantageous for real time dosimetry applications (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The narrow band gap semiconductors Bi2Te3 and Sb2Te3 are well known for their room temperature thermoelectric performance. Recently, they were shown to serve as model systems of three‐dimensional topological insulators with a bulk band gap and very robust, spin‐resolved surface states due to a special band inversion in their periodic bulk. Evidently, it is of interest to investigate the special surface states with a local probe like nuclear magnetic resonance (NMR). However, especially the bulk NMR of these materials shows peculiar and rather unexpected phenomena, e. g., a magnetic field induced deformation of the local charge symmetry and excessive line broadening due to a special internuclear coupling. Here we report a comprehensive account of the room temperature NMR properties of the spin‐1/2 nucleus 125Te of single crystalline Bi2Te3 and Sb2Te3. This includes a very unusual spin‐lattice relaxation that seems not to be reflected in the NMR shift, as well as an exchange enhanced NMR line broadening. [ABSTRACT FROM AUTHOR]