Articles you may be interested inLuminescence properties and scintillation response in Ce3+-doped Y2Gd1Al5-xGaxO12 (x = 2, 3, 4) single crystals J. Appl. Phys. 116, 083505 (2014); 10.1063/1.4893675Yttrium antisite reduction and improved photodiode performance in Ce doped Y3Al5O12 by Czochralski growth in alumina rich melts Czochralski growth of cerium-doped Lu 1.8 Y 0.2 SiO 5 ͑LYSO͒ from a 90/10 solution of Lu 2 SiO 5 ͑LSO͒ and Y 2 SiO 5 ͑YSO͒ is demonstrated. The alloyed scintillator retains the favorable growth properties of YSO and the desirable physical and optical scintillator properties of LSO. Radioluminescence, thermally stimulated luminescence, optical absorption, and lifetime measurements confirm the equivalence of LYSO and LSO optical properties. Advantages of LYSO Czochralski growth relative to LSO include reduced melting point, less propensity for formation of crystalline inclusions, lower cost of starting material, and easier incorporation of cerium into the host lattice. This material offers an attractive alternative to LSO for scintillator applications.

We measure the longitudinal (p xx ) and Hall (p xv ) resistivities as a function of magnetic field and temperature in the mixed state of epitaxial YBa2Cu3C>7 films. We observe a striking power-law behavior p xy {T) oc [p xx (T)] a at fixed field, with a -1.7 ±0.2. Our results link the Hall behavior to collective behavior in the presence of pinning. In addition, this power-law dependence is consistent with new calculations for the vortex-glass transition, and therein may provide the first measurement of a new critical exponent.

SrRuO3 thin films were deposited on (100) LaAlO3 using pulsed laser deposition. The films were (001) oriented normal to the substrate surface with a high degree of in-plane orientation with respect to the substrate’s major axes. An ion beam minimum yield of 2.5% was obtained for the films, indicating high crystallinity. The films exhibited metallic behavior with a room temperature resistivity of ∼200 mW cm. A kink in the resistivity, corresponding to a ferromagnetic phase transition, was observed at ∼160 K. It was found that SrRuO3 is structurally and chemically compatible with the YaB2Cu3O7−d (YBCO) superconductors. High quality YBCO films were obtained on SrRuO3 LaAlO3. Multilayers of YBCO/SrRuO3 were successfully fabricated.

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Photoluminescence ͑PL͒, radioluminescence ͑RL͒, and thermoluminescence ͑TL͒ investigation of Y 2 O 3 : Bi nanophosphors prepared by solution combustion synthesis using urea, glycine, and hexamethylenetetramine ͑HMT͒ as fuels was carried out. The as-prepared nanopowders have increasing crystallinity and average crystallite sizes for urea, glycine, and HMT, respectively. Luminescence is composed of two emission bands centered at 408 and 505 nm due to two nonequivalent Bi 3+ sites with symmetry S 6 and C 2 , respectively. The occupancy of these sites depends on the synthesis conditions, in agreement with theoretical predictions. Annealing at 1000°C for 1 h improves PL and RL efficiency due to enhanced crystallinity of the nanopowders and activation of recombination centers ͑Bi 3+ ions͒. No shift in the PL peak position was observed as a function of average crystallite size. The concentration quenching was experimentally determined to have a maximum emission of around 3 mol % of the dopant. TL spectra present several peaks between 50 and 300°C, and the total TL signal is correlated with the heat of combustion of the fuel and thus crystallinity increases. Most likely, increases in RL and TL are also due to the increase in the concentration of recombination centers.