Co-reporter:Binglong Liu, Jiang Li, Roman Yavetskiy, Maxim Ivanov, Yanping Zeng, Tengfei Xie, Huamin Kou, Shangjun Zhuo, Yubai Pan, Jingkun Guo
Journal of the European Ceramic Society 2015 Volume 35(Issue 8) pp:2379-2390
Publication Date(Web):August 2015
DOI:10.1016/j.jeurceramsoc.2015.02.014
Well-dispersed yttria nanopowders were synthesized by a precipitation method from yttrium nitrate solution using ammonium hydrogen carbonate as a precipitant. Needle-like precursor Y2(CO3)3·2.79 H2O undergoes fragmentation and decomposition into isolated quasi-spherical Y2O3 particles upon calcination in air. Highly transparent YAG ceramics were fabricated from the as-synthesized Y2O3 powder and the commercial α-Al2O3 powder by vacuum sintering. Phase transformation, morphology evolution, and sinterability of Y2O3 powders, microstructure and optical properties of YAG ceramics were investigated in detail. The densification, grain growth, linear shrinkage and phase transformation of the as-sintered ceramics were also explored. The activation energy for grain growth in the ceramic sample is 881 kJ/mol. With optimized preparation conditions, YAG ceramics with the average grain size of about 20 μm were fabricated by sintering at 1780 °C for 20 h, whose in-line transmittance reached 83.7% and 80.3% at the wavelength of 1064 nm and 400 nm, respectively.
Co-reporter:Siqinbilige;Rong Qian;Fuxi Gan
Chinese Journal of Chemistry 2011 Volume 29( Issue 6) pp:1251-1255
Publication Date(Web):
DOI:10.1002/cjoc.201190232
Abstract
Element characteristics of nephrite minerals were determined by glow discharge mass spectrometry (GD-MS) through surface adherence method. To solve the conductivity problem of non-conductive nephrite samples, high purity indium pin (>99.9999%) was used as discharge host. During the preparation procedure, a small piece of nephrite sample was ground into powder (about 200 meshes), and then the sample powder was coated on the surface of indium pin to form a rod sample. Typical elements of nephrite minerals were analyzed by GD-MS, and the relative standard deviations showed that the stability and reproducibility of this method were good. Meanwhile, four nephrite samples from two different deposits were further studied by this method. The GD-MS results of major elements and trace elements revealed that typical elements of the nephrite minerals from same deposit were similar, and those from different deposits exhibited significant difference. In addition, results of external-beam proton induced X-ray emission (PIXE) were consistent with the result of GD-MS determination. The present approach had been proven to be simple, efficient to perform the rapid screening and multi-element semi-quantitative analysis of nephrite samples.
Co-reporter:X.Y. Han, S.J. Zhuo, R.X. Shen, P.L. Wang, G.Y. Tao, A. Ji
Spectrochimica Acta Part B: Atomic Spectroscopy 2006 Volume 61(Issue 1) pp:113-119
Publication Date(Web):January 2006
DOI:10.1016/j.sab.2005.10.012
Theoretical equations to calculate fluorescence intensity enhanced by scattering effects for coating samples were developed based on fundamental parameter models. The secondary enhancement by scattering radiation from the same layer or between layer and substrate and the primary fluorescence that was scattered into the direction of detector by atoms in layer and substrate were included in calculations. The contributions of different scattering effects to fluorescence intensity were calculated for a hypothetical Zn coating on infinite Fe substrate sample. The results show that the contributions of scattering effects to fluorescence intensity are related to the thickness of coating and are up to several percents of primary fluorescence intensity.
Co-reporter:Xiaoyuan Han, Shangjun Zhuo, Peiling Wang, Guangyi Tao, Ang Ji
Analytica Chimica Acta 2005 Volume 538(1–2) pp:297-302
Publication Date(Web):4 May 2005
DOI:10.1016/j.aca.2005.02.023
