3at. % Eu3+ doped (Y, Gd)2O3 precursor powders with various compositions were synthesized via a sol-gel process, and the precursors were sintered at different temperatures. XRD, FT-IR, Raman and photoluminescence spectroscopy were used to study the phase, microstructure and luminescent properties of the precursors and the sintered powders. The results show that pure (Y, Gd)2O3 polycrystalline phase can be obtained from sintering the precursors at 700°C. The influences of the host compositions on the microstructures and fluorescence properties were analyzed, and the optimized composition was obtained for 3at. % Eu3+ doped (Y, Gd)2O3 powders.

采用溶液法合成甲胺溴铅(CH3NH3PbBr3)多晶原料,用溶液蒸发法生长了尺寸约为7mm×7 mm×3 mm的CH3NH3PbBr3晶体.测量了晶体的XRD谱,采用X射线外推法研究了晶体结构.结果表明:生长的CH3NH3PbBr3单晶为立方晶系结构,晶格参数a=0.59276(7) nm.将微型溶液晶体生长装置与荧光共聚焦显微镜相结合,实时观测了不同生长条件下CH3NH3PbBr3晶体的微观形貌和不同晶面的生长速率.得到(011)、(101)和(001)晶面的平均水平生长速率分别为0.017 57(6)、0.02144(4)和0.01865(7) nm/s;发达晶面簇为{110}和{100}.

In this work, large‐sized CH 3 NH 3 PbBr 3 single crystals were successful grown using solution evaporation method with hydrohalic acid and N, N‐Dimethylformamide (DMF) as solvent respectively. The lattice parameters of cubic CH 3 NH 3 PbBr 3 were estimated using XRD method. The solubility of CH 3 NH 3 PbBr 3 in hydrobromic acid was determined at the temperature range between 20 °C–90 °C. A special micro‐solution crystallizer was designed to in‐situ study the morphology of CH 3 NH 3 PbBr 3 crystal. The largest crystal face was indexed by the XRD patterns and it would be {110} for CH 3 NH 3 PbBr 3 grown from HBr solution and {100} from DMF solution. The results show that solvent would affect the morphology and crystal habit greatly during crystal growth from solution.

Polycrystalline Cr,Nd:GSAG powders were synthesized by co-precipitation method using NH4OH as the precipitant. XRD, TG/DTA, FT-IR and Raman spectroscopy were used to characterize the structural properties of the precursor and the powders sintered at different temperatures. It was found that pure GSAG polycrystalline phase was obtained by sintering the precursor at 900 degrees C. The structure of the Cr,Nd:GSAG powder sintered at 1000 degrees C was refined using the Rietveld method. The lattice parameters are a = b = c = 12.4370(4) angstrom, with alpha = beta = gamma = 90 degrees. The highest photoluminescence intensity was achieved for the powder sintered at 1100 degrees C and optical properties of powders of different Cr3+ ions concentration were characterized by using photoluminescence spectroscopy. (C) 2014 Elsevier B.V. All rights reserved.