7783-68-8Relevant articles and documents
Synthesis and characterization of a novel alkaline earth niobate Ca0.5Sr0.5Nb2O6
Dudhe,Nagdeote,Palikundwar
, p. 55 - 60 (2016)
Ca0.5Sr0.5Nb2O6 (CSN), a novel compound with crystal structure similar to the well-known orthorhombic columbite compound CaNb2O6 (CN) of alkaline earth niobates family was synthesized by a simple co-precipitation technique. The synthesized material was characterized by using X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy, FTIR spectroscopy, and photoluminescence emission spectroscopy. It was found that the CSN compound stabilizes in P b c n space group with the improved symmetry as compared to the CN. The lattice parameters of CSN were found to be comparable with those of CN, and they are: a = 15.013 ?, b = 5.757 ? and c = 5.198 ?. The morphology of CSN and CN particles synthesized by a similar method was found to be identical. However, in CSN stronger self activated luminescence than that of CN was observed. The self-activated luminescence property of CSN was assigned to the niobate octahedral group [NbO6]7- similar to the CN.
Energy transfer from Bi3+ to Ho3+ triggers brilliant single green light emission in LaNbTiO6:Ho3+, Bi 3+ phosphors
Zhang, Xingshuang,Zhou, Guangjun,Zhou, Juan,Zhou, Haifeng,Kong, Peng,Yu, Zhichao,Zhan, Jie
, p. 13680 - 13686 (2014)
Excitation of Ho3+ and Bi3+ co-doped LaNbTiO 6 particles with 453 nm blue light gave an intense single green glow. All the phosphors were synthesized via a facile sol-gel and combustion approach, and the crystal structure, particle morphology, photoluminescence (PL) properties of the phosphors and energy transfer between Bi3+ and Ho3+ were also investigated. The large spectral overlap between the broad emission band of Bi3+ around 425-570 nm and the excitation band of Ho3+ supports the efficient energy transfer from Bi3+ to Ho3+, which enhances the PL intensity remarkably. When the PL intensity is considered, the best composition for producing green light is LaNbTiO6:4 mol% Ho3+, 2 mol% Bi3+. The luminescence mechanisms of Ho3+ doped and Ho3+/Bi 3+ co-doped in the LaNbTiO6 host were also discussed. This journal is the Partner Organisations 2014.
Fluorination of niobium compounds with fluorine for fluoride volatility method
Watanabe, Daisuke,Akiyama, Daisuke,Sato, Nobuaki
, p. 1 - 6 (2018)
Niobium is one of the fission products contained in spent nuclear fuel. Since niobium pentafluoride (NbF5) has high volatility, it is considered that niobium volatilizes with uranium hexafluoride when applying the fluoride volatility method, which is a promising pyro-reprocessing method. In this study, fluorination behavior characteristics of niobium compounds, such as reaction temperature, volatility, and reaction path, were investigated by thermogravimetric and differential thermal analyses and X-ray diffraction analysis. The target compounds were niobium metal, the niobium oxides NbO, Nb2O3, NbO2 and Nb2O5, and niobium oxyfluoride (NbO2F). All the niobium compounds reacted exothermically and were volatilized completely by the reaction with F2. It was considered that niobium volatilized as NbF5. The fluorination reactions started respectively at 180, 200, 300, and 300 °C for niobium metal, NbO, NbO2 and Nb2O5. In the fluorination of niobium oxides, the intermediate product NbO2F was also fluorinated above 300 °C and volatilized completely. Nb2O3, which seemed to be a mixture of NbO and NbO2, reacted with F2 as described by the summation of the fluorination reactions of NbO and NbO2. The reaction mechanism for the fluorination of niobium compounds obtained in this study is applicable to evaluation of the niobium transfer phenomena in the reprocessing process of the fluoride volatility method.
Mouras, S.,Hamwi, A.,Djurado, D.,Cousseins, J. C.,Fawal, Z.,et al.
, p. 115 - 120 (1989)
