The precursor of ultrafine In 2O 3 powder was prepared by the hydrolysis, peptization and gelation of InCl 3·4H 2O used as raw material. After calcination, ultrafine In 2O 3 powder was obtained. The particl...The precursor of ultrafine In 2O 3 powder was prepared by the hydrolysis, peptization and gelation of InCl 3·4H 2O used as raw material. After calcination, ultrafine In 2O 3 powder was obtained. The particles were characterized by the methods of thermo gravimetric and differential thermal analysis (TG DTA), X ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively.展开更多
A simple and rapid process for synthesizing lead zirconate titanate,Pb（Zr0.52Ti0.48）O3（PZT）,ferroclectric powders was developed.This process,combining the sol-gel and combustion process.offers several advantages o...A simple and rapid process for synthesizing lead zirconate titanate,Pb（Zr0.52Ti0.48）O3（PZT）,ferroclectric powders was developed.This process,combining the sol-gel and combustion process.offers several advantages over conventional methods.including rapid solution synthesis,use of commercially available materials lower synthesis temperature and ease of obtaining ultrafine powders.The precursor solution for synthesizing powders was prepared from lead nitrate.zireonium nitrate.titanium oxynitrate,citric acid and deionized water.The precarsor was investigated by DSC-TG,and the PZT powders were investigated by powder-XRD,IR spectra and TEM.XRD analysis shous that the powders possess a single phase perovskite type structure,no pyrochlore phase exists.and TEM image shows that the grain size of the powders is about 40nm.展开更多
The ultrafine powders of YBa2Cu3O7-x with the size of 100nm were synthesized by Sol-Gel process using cit-rate as complex and ammonium hydroxide to adjust pH of solu-tion. The process of Sol formation and Gel polymeri...The ultrafine powders of YBa2Cu3O7-x with the size of 100nm were synthesized by Sol-Gel process using cit-rate as complex and ammonium hydroxide to adjust pH of solu-tion. The process of Sol formation and Gel polymerization of YBa2Cu3O7-x in the Sol-Gel synthetic reaction has bee studied. The particle size ,pruity, sintering activity and superconducting properties of YBa2Cu3O7-x prepared by Sol-Gel method are better than by solid state reaction.展开更多
The hexagonal BaGd x Fe 12- x O 19 ( x =0.1～1.0) nano sized powders with M type structure were synthesized by the sol gel auto combustion high temperature synthesis method. The effects of pH of...The hexagonal BaGd x Fe 12- x O 19 ( x =0.1～1.0) nano sized powders with M type structure were synthesized by the sol gel auto combustion high temperature synthesis method. The effects of pH of the solution, the molar ratio of nitrate/citric acid and the calcination temperature on the synthesis of the ferrites were investigated. The crystal structure, grain size, shape and magnetic properties were studied by means of XRD, TEM and vibrating sample magnetometer.The results show that under the conditions of pH 7.0 or so, mole ratio of citrate/nitrate (1～3) and calcination temperature of 850 ℃ for 1 h, M type BaGd x Fe 12- x O 19 ultrafine powders with a particle size of less than 100 nm can be obtained, and the coercive force reaches 430 kA·m -1 at x =1.0, which is far greater than that of barium ferrite (BaFe 12 O 19 ).展开更多
With InCl 3·4H 2O being used as raw materials, the precursor of nano sized In 2O 3 powder was prepared by hydrolysis, peptization and gelation of InCl 3·4H 2O. After calcination, nano sized In 2O 3...With InCl 3·4H 2O being used as raw materials, the precursor of nano sized In 2O 3 powder was prepared by hydrolysis, peptization and gelation of InCl 3·4H 2O. After calcination, nano sized In 2O 3 powder was obtained. The powder was characterized by thermo gravimetric and differential thermal analysis (TG DTA), X ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively. Calculation revealed that the mean crystalline size increased with increasing the calcination temperature, but crystal lattice distortion rate decreased with the increasing in the average crystalline size. This indicated that the smaller the particle size, the bigger the crystal lattice distortion, the worse the crystal growing. The activation energies for growth of nano sized In 2O 3 were calculated to be 4.75 kJ·mol -1 at the calcination temperature up to 500℃ and 66.40 kJ·mol -1 at the calcination temperature over 600℃. TEM photos revealed that the addition of the chemical additive (OP-10) greatly influenced the morphology and size of In 2O 3 particles.展开更多
Ultrafine powder is widely investigated theoretically and experimentally because of its novel properties and important applications in various areas such as fine composite, catalyst, microwave absorption and optoelect...Ultrafine powder is widely investigated theoretically and experimentally because of its novel properties and important applications in various areas such as fine composite, catalyst, microwave absorption and optoelectronics. From the point of view of ceramists, ultrafine powders can be divided into two types by size accordingly. Fine powder is defined as parti-展开更多
La_2Zr_2O_7 ultrafine powders were prepared by sol-gel method.SEM indicated that La_2Zr_2O_7 particles aremosily spherical in shape and average particle sizes are smaller than 0. 5 pe XRD patterns showed that no in-to...La_2Zr_2O_7 ultrafine powders were prepared by sol-gel method.SEM indicated that La_2Zr_2O_7 particles aremosily spherical in shape and average particle sizes are smaller than 0. 5 pe XRD patterns showed that no in-tormediare phase was observed in the course of La_2Zr_2O_7 formation. The crystal structure of La_2Zr_2O_7 wasfound to be of the fluorite type when calcination temperature was 800～900℃ and of the pyrochlore type at1000℃ . The latter is cubic, its space group is Fd3m. Cxlculation of crystallite size indicated that the averagecrystallite size increased with the increasing calculation temperature. The average crystal lattice distortion ratedecreaed with the increase of particle sizes. IR spectra showed that the smaller the particles are , the higher surface activity the particles have.展开更多
Using In(NO3)3·5H2O and acetylacetone as raw materials and anhydrous SnCl4 as dopant, the transparent conducting indium tin oxide(ITO) films were prepared by sol-gel and dip-coating technique. The phase transform...Using In(NO3)3·5H2O and acetylacetone as raw materials and anhydrous SnCl4 as dopant, the transparent conducting indium tin oxide(ITO) films were prepared by sol-gel and dip-coating technique. The phase transformation, structure properties and physical properties (sheet resistance and transmittance) of the films were investigated by DTA-TG, XRD, SEM, four-probe method and UV-Vis spectrometry. The results indicate that it is feasible to fabricate ITO films on the quartz substrates by sol-gel technique, and the ITO films are formed by accumulating of particles with the size of several decades of nanometers. The prepared ITO film has cubic bixbyite structure, and (111) is its preferred plane. After five-times dip-coating, the ITO film has a thickness less than 150 nm, a sheet resistance of 110Ω/□, a resistivity of 1.65×10-3 Ω·cm and a transparency of 90%.展开更多
The Indium tin oxide（ITO） thin film possesses excellent photoelectric properties that enable it to act as an ideal transparent conductor.To obtain high-quality ITO films through sol-gel method, the ionic surfactant ...The Indium tin oxide（ITO） thin film possesses excellent photoelectric properties that enable it to act as an ideal transparent conductor.To obtain high-quality ITO films through sol-gel method, the ionic surfactant monoethanolamine and the non-ionic surfactant polyethylene glycol（PEG） were added to the ITO precursor slurry.The influences of surfactants on the structural and photoelectric properties of ITO film samples were investigated.XRD patterns indicated that surfactant monoethanolamine contributed to film predominant grain orientation along the（400） plane.The high transmittance（over 95%） was attributed to the preferred orientation and the grain size expansion of ITO films.SEM showed that the surface particle size and the morphology of ITO films were strongly dependent on the kind of surfactants used.Moving to the shortwave region, the absorption edge of the films exhibited the Burstein-Moss shift.展开更多
In the present study, niobium-doped indium oxide thin films were prepared by sol-gel spin coating technique. The effects of different Nb-doping contents on structural, morphological, optical, and electrical properties...In the present study, niobium-doped indium oxide thin films were prepared by sol-gel spin coating technique. The effects of different Nb-doping contents on structural, morphological, optical, and electrical properties of the films were characterized by means of X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, atomic force microscopy （AFM）, UV-Vis spectroscopy, and four point probe methods. XRD analysis confirmed the formation of cubic bixbyite structure of In203 with a small shift in major peak position toward lower angles with addition of Nb. FESEM micrographs show that grain size decreased with increasing the Nb-doping content. Optical and electrical studies revealed that optimum opto-electronic properties, including minimum electrical resistivity of 119.4 × 10^-3 Ω cm and an average optical transmittance of 85% in the visible region with a band gap of 3.37 eV were achieved for the films doped with Nb-doping content of 3 at.%. AFM studies show that addition of Nb at optimum content leads to the formation of compact films with smooth surface and less average roughness compared with the prepared ln2O3 films.展开更多
文摘The precursor of ultrafine In 2O 3 powder was prepared by the hydrolysis, peptization and gelation of InCl 3·4H 2O used as raw material. After calcination, ultrafine In 2O 3 powder was obtained. The particles were characterized by the methods of thermo gravimetric and differential thermal analysis (TG DTA), X ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively.
文摘A simple and rapid process for synthesizing lead zirconate titanate,Pb（Zr0.52Ti0.48）O3（PZT）,ferroclectric powders was developed.This process,combining the sol-gel and combustion process.offers several advantages over conventional methods.including rapid solution synthesis,use of commercially available materials lower synthesis temperature and ease of obtaining ultrafine powders.The precursor solution for synthesizing powders was prepared from lead nitrate.zireonium nitrate.titanium oxynitrate,citric acid and deionized water.The precarsor was investigated by DSC-TG,and the PZT powders were investigated by powder-XRD,IR spectra and TEM.XRD analysis shous that the powders possess a single phase perovskite type structure,no pyrochlore phase exists.and TEM image shows that the grain size of the powders is about 40nm.
文摘The ultrafine powders of YBa2Cu3O7-x with the size of 100nm were synthesized by Sol-Gel process using cit-rate as complex and ammonium hydroxide to adjust pH of solu-tion. The process of Sol formation and Gel polymerization of YBa2Cu3O7-x in the Sol-Gel synthetic reaction has bee studied. The particle size ,pruity, sintering activity and superconducting properties of YBa2Cu3O7-x prepared by Sol-Gel method are better than by solid state reaction.
文摘The hexagonal BaGd x Fe 12- x O 19 ( x =0.1～1.0) nano sized powders with M type structure were synthesized by the sol gel auto combustion high temperature synthesis method. The effects of pH of the solution, the molar ratio of nitrate/citric acid and the calcination temperature on the synthesis of the ferrites were investigated. The crystal structure, grain size, shape and magnetic properties were studied by means of XRD, TEM and vibrating sample magnetometer.The results show that under the conditions of pH 7.0 or so, mole ratio of citrate/nitrate (1～3) and calcination temperature of 850 ℃ for 1 h, M type BaGd x Fe 12- x O 19 ultrafine powders with a particle size of less than 100 nm can be obtained, and the coercive force reaches 430 kA·m -1 at x =1.0, which is far greater than that of barium ferrite (BaFe 12 O 19 ).
文摘With InCl 3·4H 2O being used as raw materials, the precursor of nano sized In 2O 3 powder was prepared by hydrolysis, peptization and gelation of InCl 3·4H 2O. After calcination, nano sized In 2O 3 powder was obtained. The powder was characterized by thermo gravimetric and differential thermal analysis (TG DTA), X ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively. Calculation revealed that the mean crystalline size increased with increasing the calcination temperature, but crystal lattice distortion rate decreased with the increasing in the average crystalline size. This indicated that the smaller the particle size, the bigger the crystal lattice distortion, the worse the crystal growing. The activation energies for growth of nano sized In 2O 3 were calculated to be 4.75 kJ·mol -1 at the calcination temperature up to 500℃ and 66.40 kJ·mol -1 at the calcination temperature over 600℃. TEM photos revealed that the addition of the chemical additive (OP-10) greatly influenced the morphology and size of In 2O 3 particles.
文摘Ultrafine powder is widely investigated theoretically and experimentally because of its novel properties and important applications in various areas such as fine composite, catalyst, microwave absorption and optoelectronics. From the point of view of ceramists, ultrafine powders can be divided into two types by size accordingly. Fine powder is defined as parti-
文摘La_2Zr_2O_7 ultrafine powders were prepared by sol-gel method.SEM indicated that La_2Zr_2O_7 particles aremosily spherical in shape and average particle sizes are smaller than 0. 5 pe XRD patterns showed that no in-tormediare phase was observed in the course of La_2Zr_2O_7 formation. The crystal structure of La_2Zr_2O_7 wasfound to be of the fluorite type when calcination temperature was 800～900℃ and of the pyrochlore type at1000℃ . The latter is cubic, its space group is Fd3m. Cxlculation of crystallite size indicated that the averagecrystallite size increased with the increasing calculation temperature. The average crystal lattice distortion ratedecreaed with the increase of particle sizes. IR spectra showed that the smaller the particles are , the higher surface activity the particles have.
文摘Using In(NO3)3·5H2O and acetylacetone as raw materials and anhydrous SnCl4 as dopant, the transparent conducting indium tin oxide(ITO) films were prepared by sol-gel and dip-coating technique. The phase transformation, structure properties and physical properties (sheet resistance and transmittance) of the films were investigated by DTA-TG, XRD, SEM, four-probe method and UV-Vis spectrometry. The results indicate that it is feasible to fabricate ITO films on the quartz substrates by sol-gel technique, and the ITO films are formed by accumulating of particles with the size of several decades of nanometers. The prepared ITO film has cubic bixbyite structure, and (111) is its preferred plane. After five-times dip-coating, the ITO film has a thickness less than 150 nm, a sheet resistance of 110Ω/□, a resistivity of 1.65×10-3 Ω·cm and a transparency of 90%.
基金supported by the National High-Tech Research and Development Program of China (No. 2004AA303542)
文摘The Indium tin oxide（ITO） thin film possesses excellent photoelectric properties that enable it to act as an ideal transparent conductor.To obtain high-quality ITO films through sol-gel method, the ionic surfactant monoethanolamine and the non-ionic surfactant polyethylene glycol（PEG） were added to the ITO precursor slurry.The influences of surfactants on the structural and photoelectric properties of ITO film samples were investigated.XRD patterns indicated that surfactant monoethanolamine contributed to film predominant grain orientation along the（400） plane.The high transmittance（over 95%） was attributed to the preferred orientation and the grain size expansion of ITO films.SEM showed that the surface particle size and the morphology of ITO films were strongly dependent on the kind of surfactants used.Moving to the shortwave region, the absorption edge of the films exhibited the Burstein-Moss shift.
基金Iran Initiative Nanotechnology Council for partially supporting this workMahar Fan Abzar Co.for AFM spectroscopy results
文摘In the present study, niobium-doped indium oxide thin films were prepared by sol-gel spin coating technique. The effects of different Nb-doping contents on structural, morphological, optical, and electrical properties of the films were characterized by means of X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, atomic force microscopy （AFM）, UV-Vis spectroscopy, and four point probe methods. XRD analysis confirmed the formation of cubic bixbyite structure of In203 with a small shift in major peak position toward lower angles with addition of Nb. FESEM micrographs show that grain size decreased with increasing the Nb-doping content. Optical and electrical studies revealed that optimum opto-electronic properties, including minimum electrical resistivity of 119.4 × 10^-3 Ω cm and an average optical transmittance of 85% in the visible region with a band gap of 3.37 eV were achieved for the films doped with Nb-doping content of 3 at.%. AFM studies show that addition of Nb at optimum content leads to the formation of compact films with smooth surface and less average roughness compared with the prepared ln2O3 films.
