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
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
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.
