检索结果-南通市图书馆

Effect of Bi3+ Ion Substitution on Magnetic Properties of Cobalt Nano Ferrites Prepared by sol-gel combustion method

在线全文

学校读者我要写书评

暂无评论

Soft Nanoscience Letters 2016年第3期6卷 37-44页

作者： Naraavula Suresh Kumar Katrapally Vijaya Kumar Mallareddy Institute of Engineering & Technology Secunderabad TS India Department of Physics JNTUH College of Engineering Jagtial Nachupally Karimnagar-Dist TS India

Bismuth substituted cobalt nano ferrites with the chemical composition Co Bix Fe2-x O4 (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method. The phase identification of prepared samples is characterised by X-ray powder diffraction (XRD) method, which confirms the formation of a single phase fcc spinal structure. The mean crystallite sizes of all prepared samples were obtained within the range of 21 (±5) nm. Transmission Electron Microscopy (TEM) images also confirmed the crystallite size of all the synthesised samples was in nano range. With the effect of Bi3+ ion substitution on spinal cobalt ferrite, the magnetic properties were investigated by using Vibration Sample Magnetometer (VSM). The obtained hysteresis (M-H) curves of all the samples were analysed under the applied magnetic field of range ± 10 K Oe at 300 K. The magnetic properties such as saturation magnetisation (Ms), remnant magnetization (Mr) and coercivity (Hc) values are tabulated, which show a decrease in trend as the bismuth ion concentration increases. This is due to the addition of Bi3+ ion in the place of Fe3+ ion (octahedral site) and hence the Bi3+-Fe3+ ion interaction predominates as compared with the Fe2+-Fe3+ ion interaction. The data obtained from magnetic studies, the variation among the magnetic properties have been investigated for all the prepared samples.

关键词： Bi-Co Nano Ferrites sol-gel combustion method TEM and VSM

Citrate sol-gel combustion preparation and photoluminescence properties of YAG:Ce phosphors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2012年第4期30卷 289-296页

作者：张乐陆洲朱金振杨浩韩朋德陈雁张其土 College of Materials Science and Engineering Nanjing University of Technology

Yellow-emitting YAG：Ce3＋ nanocrystalline phosphors were prepared by citrate sol-gel combustion method using citric acid as the fuel and chelating agent. The influence of mole ratio of citric acid to metallic ions （MRCM）, pH value of the solution, calcination temperature and Ce-doped concentration on the structures and properties of as-prepared powders were investigated in detail. Higher crystallinity and better luminescence performance powders were obtained at MRCM=2, pH=3 and the calcination temperature of 1200 ℃. The phosphors exhibited the charactefistc broadband visible luminescence of YAG：Ce. The optimum concentration of Ce3＋ was 1.0 tool.%, and the concentration quenching was derived from the reciprocity between electric dipole and electric quadrupole （d-q）. Especially, the pH value of the solution was a key factor to obtain a stable sol-gel system and then obtain pure and homogeneous rare earth ions doped YAG phosphors at a lower tem- perature. The Y3Al5O12：Ce0.03 phosphor with optimized synthesis-condition and composition had a similar luminescence intensity with the commercial phosphor YAG：Ce.

关键词： YAG:Ce sol-gel combustion method photoluminescence phosphors concentration quenching rare earths

Preparation and properties of Nd:YAG ultra-fine powders

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2011年第1期29卷 44-47页

作者：陈娇黄啸谷王丽熙张其土 College of Materials Science and Engineering Nanjing University of Technology Jiangsu Provincial Key Laboratory of New Materials of Inorganic and Its Composites Nanjing University of Technology

Ultra-fine Nd：YAG powders with different doping concentrations were synthesized by sol-gel combustion method. The pure Nd：YAG could be prepared at the low temperature of 900℃. Ethanol could improve the dispersity of powders, and the average size of the ultra-fine powders was around 250 nm. The reflection spectrum showed that there were several apparent characteristic absorption peaks and the intensity of these peaks enhanced with the increasing concentration of Nd^3＋. The luminescence spectrum, which was excited by 808 nm wavelength, exhibited several obvious emission bands in the range of 900-1150 nm. The emission intensity of Nd：YAG powders increased until the Nd content was above 3 mol.% due to the fluorescent quenching effect.

关键词： Nd:YAG ultra-fine powders sol-gel combustion method luminous performance rare earths

Optical property of SmAlO_3 applied as 1.06 μm laser absorbing material

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2013年第11期31卷 1102-1105页

作者：朱怡青韩朋德张乐王丽熙张其土 College of Materials Science and Engineering Nanjing University of Technology Jiangsu Provincial Key Laboratory of New Materials of Inorganic and Its Composites Nanjing University of Technology

SmAlO3 powders were successfully synthesized through the citrate sol-gel combustion method. The phase evolution of the prepared powders were characterized using thermal gravimetric （TG） analysis, differential scanning calorimetry （DSC） analysis and Fourier transform infrared spectroscopy （FTIR）. X-ray diffraction （XRD） was applied to examine the purity of the powders. The re-flective properties of SmAlO3 with changing temperatures were investigated by ultraviolet-visible near-infrared spectrophotometer （UVPC） specular reflection spectrum. The results displayed that pure SmAlO3 phase with preferable reflectivity at 1.06μm could be obtained at 900 oC for 2 h. Furthermore, the reflectivity of SmAlO3 at various temperatures from-40 to 500 oC transformed within ±0.1%, and all maintained below 1%at 1.06μm. The absorbance of SmAlO3 in the resin solution was 2.134 and the moral absorption coefficient was about 384.8 in the work. The study indicated that SmAlO3 powders may be a promising kind of heat resistant absorb-ing material for 1.06μm laser defense, which could be further applied to laser absorbing coatings with a wide range of temperatures.

关键词： SmAIO3 laser absorption heat resistant sol-gel combustion method rare earths

Synthesis and Characterization of Neodymium and Ytterbium-doped Yttrium Aluminum Garnet Nano-powder

在线全文

学校读者我要写书评

暂无评论

Journal of the Chinese Ceramic Society 2016年第2期3卷 98-101页

作者： ZHANG Xuejian BI Meng LI Chun HU Hongliang LI Shouyin LIU Jinghe Jilin Jianzhu University Changchun Structural and Functional Material Engineering Research Center Changchun University of Science and Technology Nanchang Hongkong University

Nd/Yb-co-doped YAG transparent ceramic nano-powder was prepared by a sol-gel combustion *** structure,morphology and properties were characterized by thermogravimetric-differential thermal analysis,X-ray diffraction,transmission electron microscopy,infrared spectroscopy,absorption analysis and fluorescence spectroscopy,*** results show that the mass loss of the powder calcinated at 900 ℃ for 3 h is 49.56%.A well-crystallized Nd/Yb:YAG nano-powder with the superior sintering performance and high purity is obtained,and the morphology of the particles with the average diameter in the range of 60-100 runs appears *** nano-powder exhibits an intense absorption at 808 nm,corresponding to the 4I/9/2-4F7/2 transition of Nd^(^(3+) ions,which is suitable to absorb the wavelength of 808 nm from a laser diode *** emission peak at 1046 nm of the Nd/Yb:YAG powder is more intense than that of Nd^(^(3+):YAG *** is indicated that the energy absorbed by Yb^(^(3+) ions from the laser diode source can be transmitted to Nd^(^(3+) ions based on the cross relaxation process of[(4F3/2)Nd,(2F7/2)Yb]-[(479/2)Nd,(2F5/2)Yb].

关键词： sol-gel combustion method neodymium and ytterbium-doped yttrium aluminum garnet transparent ceramics nano-powder properties characterization

Synthesis and Characterization of Neodymium and Ytterbium-doped Yttrium Aluminum Garnet Nano-powder

在线全文

学校读者我要写书评

暂无评论

Synthesis and Characterization of Neodymium and Ytterbium-do...