Synthesis of Bi4-xYbxTi3O12 Nanopowders by a Modified Sol-Gel Process

2007 ◽  
Vol 336-338 ◽  
pp. 2002-2004
Author(s):  
Xian Qun Chen ◽  
Qiu Sun ◽  
Hong Cheng Liu
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Phase Changes ◽  
Nanocrystalline Powders ◽  
Temperature Phase ◽  
Cation Substitution ◽  
Sol Gel Process

Rare earth Yb-doped bismuth titanate Bi4-xYbxTi3O12 (BYT) nanocrystalline powders were obtained by a modified sol-gel method. TG-DTA, FI-IR and XRD were used to determine the lowest heat treatment temperature. Phase changes in the formation of BYT crystalline powders were discussed by XRD. The effect of Yb3+ cation substitution for Bi3+ cation on the microstructure of BYT was also developed with XRD. The grain size of BYT nanopowders is about 40 nm determined by TEM.

Low Temperature Preparation of Mullite Whisker via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2014 ◽  
Vol 936 ◽  
pp. 975-980 ◽  
Author(s):  
Kai Lin Fu ◽  
Wei Hui Jiang ◽  
Guo Feng ◽  
Jian Min Liu ◽  
Qian Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Molten Salt ◽  
Sol Gel ◽  
Growth Direction ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Low Temperature Preparation ◽  
Sol Gel Process ◽  
Temperature Preparation

Mullite whisker was prepared at low temperature via non-hydrolytic sol-gel (NHSG) process combined with molten salt method. The influence of heat treatment temperature was studied on the morphology and the microstructure of whisker, and its growth mechanism was also described. The results show that the mullite whisker appears at the lowest temperature of 750 °C, and optimized mullite whisker can be prepared at 850 °C with the growth direction of [00, whose diameter is in the range of 170~300 nm with the aspect ratio of >30.

Load TiO2 or TiO2-N on the Porous Carbon

2012 ◽  
Vol 512-515 ◽  
pp. 1686-1689
Author(s):  
Jie Chen ◽  
Le Fu Mei ◽  
Li Bing Liao
Keyword(s):  
Heat Treatment ◽  
Porous Carbon ◽  
Heat Treatment Temperature ◽  
Treatment Time ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Heat Treatment Time ◽  
Sem Images ◽  
Soaking Time ◽  
Sol Gel Process

In this paper, porous carbon has been used to carry TiO2 and TiO2-N by a sol-gel process. The effect of soaking time, heat treatment temperature, and heat treatment time on the carrying efficiency have been studied. XRD experiments indicated that TiO2 and TiO2-N crystallized in anatase and rutile with the ratio of 3∶2. SEM images showed that island-like TiO2 and TiO2-N particles with diameters in the range of 1-5um, the biggest size is about 10um, were evenly coated on the surface of the porous carbon.

Effect of Phase Formation on Magnetism of Sol-Gel Derived PbTiO3/(Ni, Pb) Ferrite Composite Powders

2007 ◽  
Vol 336-338 ◽  
pp. 706-708 ◽  
Author(s):  
Yan Ling Dong ◽  
Pi Yi Du ◽  
Wen Jian Weng ◽  
Gao Rong Han
Keyword(s):  
Heat Treatment ◽  
Ferroelectric Phase ◽  
Sol Gel ◽  
Initial Permeability ◽  
Treatment Temperature ◽  
Ferromagnetic Phase ◽  
Composite Powders ◽  
Structure Morphology ◽  
Sol Gel Process

Ferroelectric/ferromagnetic multiphase powdered composites, consisting of PbTiO3 as ferroelectric phase and NiFe2O4 (PbFe12O19) as ferromagnetic phase, were successfully prepared in situ by sol-gel process. The phase structure, morphology and magnetism properties were observed. Biphase powdered ME composite consisting of PbTiO3 and NiFe2O4 is obtained at 700oC. Triphase composite consisting of PbTiO3, NiFe2O4 and PbFe12O19 is obtained above 750oC. With increasing heat-treatment temperature, the particles combine more tightly and the particle size decreases. The saturation magnetization (σs) and the initial permeability (μi) increase with the increase of NiFe2O4 content. The coercive force (Hc) increases with the increase of PbFe12O19 content.

Synthesis of Pb1-xYbx(Zr0.52Ti0.48)O3 Nanopowders by a Modified Sol-Gel Process Using Zirconium Oxynitrate Source

2007 ◽  
Vol 121-123 ◽  
pp. 223-226
Author(s):  
Qiu Sun ◽  
Fu Ping Wang ◽  
Zhao Hua Jiang
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Phase Changes ◽  
Nanocrystalline Powders ◽  
Cation Substitution ◽  
Memory Devices ◽  
Pzt Thin Films

Ferroelectric lead zirconate titanate(PZT)thin films have attracted great attention because of their potential applications in memory devices[1] due to their unique properties, for example, hysteresis loop and high dielectric constant. To realize these memory devices, it is necessary to overcome the reliability problems such as fatigue, retention and imprint. It is well known that lead base perovskite family ferroelectric thin films with donor dopant such as La3+ and Nb5+ have improved the electrical properties of PZT thin films effectively [2-3]. And it is proposed that the cation substitution could reduce the number of defects such as oxygen vacancies, which could promote electrical fatigue and leakage current of PZT ferroelectric thin films obviously. In the present study, rare earth Yb-doped lead zirconium titanate (PYZT) nanocrystalline powders with a composition near the morphotropic phase boundary (Zr/Ti=52/48) were prepared by a modified sol-gel method. DTA/TG and XRD were used to determine the thermal and phase changes in the formation of PYZT crystalline powders. The effect of Yb3+ cation substitution for Pb2+ cation on the microstructure of PZT was developed with XRD. The grain size of PYZT nanopowders is about 40 nm determined by TEM.

Effect of SiO2 Contents in TEOS-SiO2-OTES Hybrid Coating on Glass

2019 ◽  
Vol 798 ◽  
pp. 128-133 ◽  
Author(s):  
Kanit Tapasa ◽  
Usanee Pantulap ◽  
Benjamon Petchareanmongkol ◽  
Waraporn Kaewdang
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Spin Coating ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Hybrid Coating ◽  
Glass Slide ◽  
Hydrophobic Property ◽  
Vis Spectroscopy ◽  
Sol Gel Process

This work aims to study the effect of SiO2 and heat treatment temperature in TEOS-SiO2-OTES film on the hydrophobic property and weathering durability. TEOS-SiO2-OTES film was prepared by sol-gel process. Tetraethylorthosilicte (TEOS) and Octyltriethoxysilane (OTES) were used to form the gel. The contents of SiO2 were varied at 0.5% 1% 3% 5% and 10% by weight. The film was deposited on a glass slide by spin coating. The hydrophobic property was studied by FTIR, UV-VIS spectroscopy, SEM, XRD and contact angle. The weathering chamber was used for studying weathering durability. The weathering condition was controlled at 50 oC and 85%RH. Moreover, the chemical resistant was also tested. The study showed that the silica contents affected the surface roughness of film. The surface roughness of film decreased with increasing amounts of SiO2.

scholarly journals Upconversion and infrared emission of Er3+/Yb3+ co-doped SiO2-Gd2O3 obtained by sol-gel process

2015 ◽  
Vol 9 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Leonardo Rocha ◽  
Sidney Ribeiro ◽  
Arnaldo Pereira ◽  
Marco Schiavon ◽  
Jefferson Ferrari
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Sol Gel ◽  
Infrared Region ◽  
Infrared Emission ◽  
Treatment Temperature ◽  
Cubic Phase ◽  
Heat Treated ◽  
Sol Gel Process ◽  
Co Doped

This work reports on the preparation of materials based on Yb3+/Er3+ co-doped SiO2-Gd2O3 via sol-gel process. The 0.4mol%of Er3+ ions was fixed and the amount of Yb3+ ions changed as 1.8, 5 and 9mol%in order to evaluate the photoluminescence properties as a function of the Yb3+ ions concentration. The prepared xerogels were heat-treated at 900, 1000 and 1100?C for 8 h. X-ray diffraction analyses of the heat-treated materials confirmed the formation of the Gd2O3 cubic phase embedded in the SiO2 host, demonstrating the effective incorporation of RE3+ ions in the structure. The Scherrer?s equation verified that the sizes of Gd2O3 nanocrystallite are between 31 and 69 nm and directly dependent on the heat-treatment temperature. Under excitation at 980 nm all materials showed upconversion phenomena, and the intensities of the emissions in the green and red regions showed to be directly dependent on power pump of laser, quantity of Yb3+ ions and heat-treatment temperature. The materials also showed emission in the infrared region with the maximum around 1530 nm, assigned to the transition of 4I13/2 ? 4I15/2 of the Er3+ ions, region known as technological C-telecom band used in optical amplification.

scholarly journals Sintering Pmperature-Dependence on Radiopacity of Bi(2−x) ZrxO(3+x/2) Powders Prepared by Sol-Gel Process

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1685 ◽  
Author(s):  
May-Show Chen ◽  
Shih-Hsun Chen ◽  
Fu-Chih Lai ◽  
Chin-Yi Chen ◽  
Ming-Yuan Hsieh ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Zirconium Oxide ◽  
Sol Gel ◽  
Dental Materials ◽  
Particle Surface ◽  
Treatment Temperature ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ir Transmission

Bismuth oxide (Bi2O3) is an effective additive used to enhance radiography resolution for dental materials. However, there are potential concerns regarding its biocompatibility and connection to tissue discoloration. In the present study, we modified the radiopacity properties of Bi2O3 with zirconium oxide (ZrO2) using a sol-gel process and investigated the composition, as well as the effects of heat treatment temperature using Thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The harvested Bi2−xZrxO3+x/2 particles showed that the dominant phase transferred from α-Bi2O3 to β-Bi7.38Zr0.62O12.31 after a heat treatment of over 750 °C for 2 h. As the x values of Bi2−xZrxO3+x/2 increased from 0.2 to 1.0, more zirconium oxide precipitated onto the particle surface, thus enhancing the surface roughness of particles. For sol-gel Bi1.8Zr0.2O3.1 powders (x = 0.2), the radiopacity values became 4.90 ± 0.23 and 5.83 ± 0.22 mmAl after a heat treatment of 500 °C and 750 °C, respectively.

Effect of Process Parameters on Crystal Types and Microstructure of TiO2 Nanocrystalline Powders

2018 ◽  
Vol 921 ◽  
pp. 99-104
Author(s):  
Xiao Li Ming ◽  
Zhan Hong Ma ◽  
Liu Shuan Yang ◽  
Feng Zhang Ren
Keyword(s):  
Heat Treatment ◽  
Process Parameters ◽  
Luminescence Band ◽  
Room Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Nanocrystalline Powders ◽  
Strong Luminescence ◽  
Strong Luminescence Band

TiO2 nanocrystalline powders were prepared by sol-gel method with different process parameters. The phase, morphology and the luminescent property of TiO2 nanocrystalline powders were characterized by XRD, SEM and PL, respectively. The results indicated that the synthesized TiO2 nanocrystalline powders were transformed from anatase into rutile with the increasing of heat treatment temperature, which begin at the temperature of 500 oC and was almost completed at the temperature of 700 oC. And with the increasing of pH value the rutile proportion become larger, the nanograins become fine and powders agglomeration was decreased. The good performance TiO2 nanocrystalline powders were obtained when prepared temperature was 500°Cand pH value was 4. PL results show broad and strong luminescence band appeared near 470nm when TiO2 nanocrystalline powders were excited at 325nm at room temperature.

The crystallization of thin-film ceramics

1992 ◽  
Vol 50 (1) ◽  
pp. 338-339
Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Sol Gel ◽  
Processing Route ◽  
Small Areas ◽  
Ceramic Thin Films ◽  
Complex Shapes ◽  
Sol Gel Process ◽  
Ceramic Precursors ◽  
Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

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