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Production of HfO_2 thin films using different methods: chemical bath deposition, SILAR and sol–gel process

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International Journal of Minerals,Metallurgy and Materials 2014年第8期21卷 832-838页

作者： .A.Kariper Education Faculty Erciyes University

Hafnium oxide thin films （HOTFs） were successfully deposited onto amorphous glasses using chemical bath deposition, successive ionic layer absorption and reaction （SILAR）, and sol-gel methods. The same reactive precursors were used for all of the methods, and all of the films were annealed at 300℃ in an oven （ambient conditions）. After this step, the optical and structural properties of the films produced by using the three different methods were compared. The structures of the films were analyzed by X-ray diffTaction （XRD）. The optical properties are investigated using the ultraviolet-visible （UV-VIS） spectroscopic technique. The film thickness was measured via atomic force microscopy （AFM） in the tapping mode. The surface properties and elemental ratios of the films were investigated and measured by scanning electron microscopy and energy-dispersive X-ray spectroscopy （EDX）. The lowest transmittance and the highest reflectance values were observed for the films produced using the SILAR method. In addition, the most intense characteristic XRD peak was observed in the diffraction pattern of the film produced using the SILAR method, and the greatest thickness and average grain size were calculated for the film produced using the SILAR method. The films produced using SILAR method contained fewer cracks than those produced using the other methods. In conclusion, the SILAR method was observed to be the best method for the production of HOTFs.

关键词： hafnium oxide thin films optical properties structural properties chemical deposition absorption sol-gel process

UV-Irradiation Cured Organic-inorganic Hybrid Nanocomposite Initiated by Ethoxysilane-modified Multifunctional Polymeric Photoinitiator through sol-gel process

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Chinese Journal of Chemistry 2011年第9期29卷 1961-1968页

作者： Hu, Lihua Shi, Wenfang Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei Anhui 230026 China

The UV-cured organic-inorganic hybrid nanocomposite （nano-Si-m-PI） was prepared through the photopolymeri- zation of acrylic resin initiated by ethoxysilane-modified multifunctional oligomeric photoinitiator （Si-m-PI）. The es- terification reaction of 2-hydroxy-4＇-（2-hydroxyethoxy）-2-methylpropiophenone （Irgacure 2959） with thioglycolic acid, and the following addition reactions with dipentaerythritol hexaacrylate and then 3-aminopropyltriethoxysilane were carried out for preparing the Si-m-PI. The Si-m-PI exhibits the similar UV absorption and molar extinction coefficient with Irgacure 2959. The photoinitiating activity study by photo-DSC analysis showed that the Si-m-PI possesses high photopolymerization rate at the peak maximum （Rpax） and final unsaturation conversion （Pf） in the cured hybrid films. From the scanning electron microscope （SEM） observation, the SiO2 nanoparticles dispersed uniformly in the formed nano-Si-m-PI, whereas the aggregation of nanoparticals occurred in nano-Irg, which was prepared through the photopolymerization of acrylic resin initiated by Irgacure 2959. Moreover, compared with the UV-cured pure polymer and nano-Irg, the nano-Si-m-PI showed remarkably enhanced thermal stability and mechanical properties.

关键词： polymer-matrix composites sol-gel process mechanical property UV-curing

Structure,room-temperature magnetic and optical properties of Mn-doped TiO_2 nano powders prepared by the sol-gel process

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Chinese Physics B 2010年第11期19卷 667-672页

作者：丁芃刘发民周传仓钟文武张嬛蔡鲁刚曾乐贵 Department of Physics School of Physics and Nuclear Energy EngineeringKey Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education)Beijing University of Aeronautics and Astronautics

TiO2 nano powders with Mn concentration of 0 at%-12 at% were synthesized by the sol-gel process, and were annealed at 500 ℃ and 800 ℃ in air for 2 hrs. X-ray diffraction （XRD） measurements indicate that the Mn-TiO2 nano powders with Mn concentration of 1 at% and 2 at% annealed at 500 and 800 ℃ are of pure anatase and rutile, respectively. The scanning electron microscope （SEM） observations reveal that the crystal grain size increases with the annealing temperature, and the high resolution transmission electron microscopy （HRTEM） investigations further indicate that the samples are well crystallized, confirming that Mn has doped into the TiO2 crystal lattice effectively. The room temperature ferromagnetism, which could be explained within the scope of the bound magnetic polaron （BMP） theory, is detected in the Mn-TiO2 samples with Mn concentration of 2 at%, and the magnetization of the powders annealed at 500 ℃ is stronger than that of the sample treated at 800 ℃. The UV-VIS diffuse reflectance spectra results demonstrate that the absorption of the TiO2 powders could be enlarged by the enhanced trapped electron absorption caused by Mn doping.

关键词： Mn-doped TiO2 nano powders sol-gel process room-temperature magnetic properties diffuse reflectance spectra

Review on sol-gel Derived Coatings: process, Techniques and Optical Applications

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Journal of Materials Science & Technology 2002年第3期18卷 211-218页

作者： S.M.Attia JueWANG 等 PohlInstituteofsolidStatePhysics TongjiUniversityShanghai200092China Phys.Dept.FacultyofEducation KaferEl-SheikhEgypt

sol-gel process is one of the simplest techniques to manufacture thin films. The quality of the prepared films depends on the parameters of the sol-gel process and the technique used for deposition. A great variety of the sol-gel derived films have been prepared for different applications. These sol-gel derived coatings are reviewed. The sol-gel deposition process is introduced in detail. Different sol-gel deposition techniques are mentioned. The optical applications of the sol-gel derived coatings are reviewed.

关键词： sol-gel process Coating Thin film

Electrical transport and thermoelectric properties of Ni-doped perovskite-type YCo_(1-x)Ni_xO_3 (0 ≤ x ≤ 0.07) prepared by sol-gel process

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Chinese Physics B 2013年第5期22卷 456-461页

作者：刘义李海金张清李勇刘厚通 School of Mathematics and Physics Anhui University of Technology

Electrical transport and thermoelectric properties of Ni-doped YCOl-xNixO3 （0 ≤ x ≤0.07）, prepared by using the sol-gel process, are investigated in a temperature range from 100 to 780 K. The results show that with the increase of Ni doping content, the values of DC resistivity of YCo 1-xNixO3 decrease, but carder concentration increases. The temperature dependences of the resistivity for YCOl-xNixO3 are found to follow a relation of lnp o, lIT in a low-temperature range （LTR）（T 〈- 304 K for x = 0; - 230 K 〈 T 〈- 500 K for x = 0.02, 0.05, and 0.07） and high-temperature range （HTR）（T 〉-655 K for all compounds）, respectively. The estimated apparent activation energies for conduction Eal in LRT and Ea2 in HTR are both found to decrease monotonically with doping content increasing. At very low temperatures （T 〈-230 K）, Mott＇s law is observed for YCOl-xNixO3 （x≥ 0.02）, indicating that considerable localized states form in the heavy doping compounds. Although the Seebeck coefficient of the compound decreases after Ni doping, the power factor of YCOl-xNixO3 is enhanced remarkably in a temperature range from 300 to 740 K, i.e., a 6-fold increase is achieved at 500 K for YCo0.98Ni0.0203, indicating that the high-temperature thermoelectric property of YCoO3 can be improved by partial substitution of Ni for Co.

关键词： perovskite cobalt oxides sol-gel process electrical transport thermoelectric property

SYNTHESIS AND OPTICAL PROPERTIES OF A NOVEL ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL POLYMER VIA sol-gel process

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Chinese Journal of Polymer Science 2001年第4期19卷 421-427页

作者： Hong-xia Xi Zhong Li Zhao-xi Liang The Institute of Chemical Engineering South China University Guangzhou 510640 China The Institute of Polymer Science, Zhongshan University Guangzhou 510275, China 华南理工大学广东广州中山大学广东广州

A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e, gamma -isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR,H-1-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces low dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r(33)) of 7.1 pm/V at 1.1 mum wavelength, and exhibit good SHG stability, the r(33) values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3% at 100 degreesC for 300 min.

关键词： sol-gel process nonlinear optical material alkoxysilane dye dipole alignment relaxation chromophore

Photoluminescence properties of an orange-red LaSr_(2)AlO_(5):Sm^(3+)phosphor prepared by the Pechini-type sol-gel process

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Journal of Rare Earths 2015年第9期33卷 954-960页

作者：顾席光傅仁利蒋维娜张鹏飞汤晔 Arzu COSGUN College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics

LaSr2A1Os：Sm3＋ phosphors were synthesized by the Pechini-type sol-gel process. The X-ray diffraction pattern revealed that a pure LaSr2AIO5 phase was obtained with a sintering temperature of 1200 ℃. Microstructure characterization showed that the particles were spherical in shape with a mean size of 2.93 μm. Being a candidate orange/red emitting phosphor for orange and white light emitting diodes, LaSr2A1Os：Sm3＋ could be effectively excited by both near-ultraviolet （NUV） and blue lights with typical f-f transitions of Sm3＋ ions. The most intense emission corresponding to 4G5/2---＊6H7/2 （604 nm） could be achieved at the same Sm3＋ concentration of 4 mol.%. The chromaticity coordinates of La0.96Sr2A1Os：0.04Sm3. phosphor under the excitation of 407 and 458 nm were （0.57, 0.43） and （0.59, 0.38）, respectively. Further study was carried out using Van Uitert＇s and Dexter＇s models. A consistent result was obtained that electric dipole-dipole interaction was dominant for the energy transfer among Sm3＋ ions. The critical distance for energy transfer among Sm3＋ ions in LaSr2A105 was calculated to be ca. 1.843 nm.

关键词： photoluminescence LaSr2AlO5 Sm3+ phosphors sol-gel process rare earths

Growth of TiO_2 Nanorods by sol-gel Template process

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Journal of Materials Science & Technology 2007年第5期23卷 611-613页

作者： A.Sadeghzadeh Attar Sh.Mirdamadi F.Hajiesmaeilbaigi M.Sasani Ghamsari Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran solid State Laser Research Group Laser Research Center11365-8486TehranIran

In this work, TiO2 nanorods with uniform diameter of about 100 nm and a length of several micrometers were successfully prepared by the sol-gel template method. Also the influence of molar ratios of precursor on the morphology and structure of TiO2 nanorods has been investigated. The prepared samples were characterized by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The XRD results indicated that the TiO2 nanorods were crystallized in the anatase and rutile phases, after annealing to 400-700℃ up to 2 h.

关键词： TiO2 nanorods sol-gel process Template-based growth

Hydroxyapatite/alumina nanocrystalline composite powders synthesized by sol–gel process for biomedical applications

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1033-1036页

作者： S.Khors M.H.Fathi S.Salehi S.Amirkhanlou Young Researchers and Elite Club Najafabad Branch Islamic Azad University Department of Materials Engineering Isfahan University of Technology German Textile Research Centre North-West (DTNW) University of Duisburg-Essen Young Researchers and Elite Club Behshahr Branch Islamic Azad University

Hydroxyapatite/alumina nanocrystalline composite powders needed for various biomedical applications were successfully synthe- sized by sol-gel process. Structural and morphological investigations of the prepared composite powders were performed using X-ray dif- fractometer （XRD）, scanning electron microscopy （SEM）, X＇Pert HighScore software, and Clemex Vision image analysis software. The re- suits show that the crystallite size of the obtained composite powders is in the range of 25 to 90 nm. SEM evaluation shows that the obtained composite powders have a porous structure, which is very useful for biomedical applications. The spherical nanoparticles in the range of 60 to 800 nm are embedded in the agglomerated clusters of the prepared composite powders.

关键词： nanocrystalline materials biomaterials hydroxyapatite alumina sol-gel process nanostructures