非晶Nb_(2)O_(5)晶化中间态的微观结构及晶化动力学  

Microstructure and Kinetics of Intermediate Crystallization State of Amorphous Nb_(2)O_(5)

作　　者：申星梅[1,2] 朱宗建 徐致远 武杏荣[1] 曹发斌[1] 李辽沙[1] SHEN Xingmei;ZHU Zongjian;XU Zhiyuan;WU Xingrong;CAO Fabin;LI Liaosha(Key Laboratory of Metallurgical Emission Reduction&Resources Recycling of Ministry of Education,Anhui University of Technology,Maanshan 243002,Anhui,China;AnHui Province Key Laboratory of Metallurgy Engineering&Resources Recycling,Anhui University of Technology,Maanshan 243002,Anhui,China)

机构地区：[1]安徽工业大学教育部冶金减排与资源综合利用重点实验室,安徽马鞍山243002 [2]安徽工业大学冶金工程与资源综合利用安徽省重点实验室,安徽马鞍山243002

出　　处：《硅酸盐学报》2022年第5期1292-1300,共9页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51302003)。

摘　　要：Nb_(2)O_(5)有多种晶态,其形成长程有序结构的中间过程却不清楚。采用溶胶-凝胶法制备了Nb_(2)O_(5)前驱体,460~520℃煅烧得到非晶Nb_(2)O_(5)晶化中间态样品,研究了其晶体结构、形貌结构、孔结构和晶化动力学。结果表明:样品的原子有序化过程是从1.0 nm短程序的非晶态到1.0 nm短程序的少量晶体、非晶混合态,再到1.5 nm中程序的伪六方、非晶混合态,再到大于2.0 nm长程序的伪六方、正交、少量非晶混合态。煅烧温度大于495℃时,样品结晶度增长迅速,从20%增至86%。样品颗粒由大量片状和少量棒状结构交错堆积而成;从短程序到长程序转变阶段,主要是片状颗粒的生长过程,棒状颗粒没有明显变化。样品颗粒为介孔结构,随着煅烧温度的升高,逐渐以10 nm孔为主。样品Avrami指数n=1~2,主要形核方式是表面形核;且短程序向中程序转化阶段,存在晶化孕育期。以此,为Nb_(2)O_(5)晶化中间态的研究提供工作基础,从而开拓新的研究方向。Nb_(2)O_(5)has a variety of crystalline states.However,the intermediate process of forming a long-range ordered structure is still unclear.Nb_(2)O_(5)precursor was prepared by a sol-gel method.The intermediate-state samples in the crystallization of amorphous Nb_(2)O_(5)were obtained at 460℃-520℃.The crystal structure,morphology,pore structure and crystallization kinetics of the intermediate-state samples were investigated.The results show that the atomic ordering process of the sample is from 1.0 nm short-range order with an amorphous state,to 1.0 nm short-range order with a small amount of crystal and amorphous mixed state,to 1.5 nm medium-range order with a pseudo hexagonal and amorphous mixed state,and then to more than 2.0 nm long-range order with a pseudo hexagonal,orthorhombic and a small amount of amorphous mixed state.The crystallinity of the samples at>495℃increases rapidly from 20%to 86%.The samples are formed due to the crisscross accumulation of massive flaky particles and a small amount of rod-shaped particles.From a short-range order to a long-range order,the growth process of flake particles is the main process,while the rod-shaped particles have little change.The particles are mesoporous,and the size of the main pore becomes 10 nm as the calcination temperature increases.The Avrami index(n)of the samples is 1-2,and the main nucleation mode is the surface nucleation.During the transformation from short program to medium program,there exists a crystallization incubation period.This study provides a working basis for the investigation of Nb_(2)O_(5)crystallization intermediate state.

关 键 词：五氧化二铌 溶胶-凝胶 微观结构 晶化动力学 

分 类 号：TB321[一般工业技术—材料科学与工程]