RESEARCH ACTIVITIES   Transition Metal Ions Doped Nanowires and Nanoparticles   127. Hong-Tao Sun, Fumiaki Shimaoka, Jian Ruan, Yuji Miwa, Minoru Fujii, Jianrong Qiu, Minoru Mizuhata, Shigehito Deki, and Shinji Hayashi, “Highly Efficient Broadband Near-infrared Luminescence in Ni2+-doped Glass Ceramics Films Containing Cordierite Nanocrystals,” Journal of Non-Crystalline Solids, Vol. 355, pp.2425–2428 (2009). We report on highly efficient broadband near-infrared photoluminescence (PL) in Ni2+-doped glass ceramics (GCs) films fabricated by annealing Si/Ni2+-doped glass superlattices (SNGS). Over two orders of magnitude enhancement of PL can be achieved in comparison with that from the annealed glass film. The PL lifetime of the annealed SNGS is several milliseconds, which is much longer than those of bulk GCs. The strong PL enhancement results from the formation of high-quality cordierite nanocrystals because the Si layers act as Si source for the crystal growth. This technique can be extended to fabricate other types of high-quality GCs films. 118. Hong-Tao Sun, Minoru Fujii, Noriko Nitta, Minoru Mizuhata, Hidehiro Yasuda, Shigehito Deki, and Shinji Hayashi, "Molten-Salt Synthesis and Characterization of Nickel Doped Forsterite Nanocrystals,” Journal of the Americal Ceramic Society, Vol. 92, No. 4, pp. 962–966 (2009). Nickel-doped forsterite (Ni2+:Mg2SiO4) nanocrystals have been synthesized by a facile molten-salt approach in the presence of NaCl and a surfactant (NP-7.5). The products were characterized by X-ray diffraction, transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction (SAED), and luminescence spectra measurements. The crystal size could be controlled by tailoring the synthesis parameters. TEM, high-resolution TEM, and SAED results revealed the single crystalline character of Mg2SiO4 nanoparticles. A possible model for the growth of Ni2+:Mg2SiO4 nanocrystals was postulated. The obtained Ni2+:Mg2SiO4 nanocrystals show strong, super broad, near-infrared luminescence at room temperature. These doped Mg2SiO4 nanocrystals are promising gain mediums for super broadband optical amplification. 112. Hong-Tao Sun, Fumiaki Shimaoka, Minoru Fujii, Noriko Nitta, Minoru Mizuhata, Hidehiro Yasuda, Shigehito Deki, and Shinji Hayashi, "One-Step Synthesis and Near-Infrared Luminescent Properties of Er3+ and Ni2+ Doped Single-Crystalline Al18B4O33 Nanorods,” Nanotechnology, Vol. 20, 035604, pp. 1-5, December (2008). Er3+ and Ni2+ doped single-crystalline Al18B4O33 nanorods were synthesized by a facile one-step toxic-free combustion method. The products were characterized by x-ray diffraction, transmission electron microscopy, selected area electron diffraction, and integrated and time-resolved photoluminescence (PL) measurements. The phase purity, morphology, and PL properties of Er3+ and Ni2+ doped Al18B4O33 nanorods can be readily controlled by tailoring the annealing temperature. The mechanism for the formation of Al18B4O33 nanorods with different aspect ratio is discussed. Er3+ doped Al18B4O33 nanorods show strong PL centered at 1531 nm, while Ni2+ doped products show superwide PL with a full width at half maximum of up to 250 nm. These aluminum borate nanostructures are promising building blocks for optoelectronics nanodevices.