镧修饰钛酸钡纳米多晶粉体及陶瓷传感元件的工艺优化及特性表征  

Processing optimization and characterization of La_xBa_(1-x)TiO_3 nanosized polycrystalline powder and ceramic sensor

作　　者：王智民[1] 陈旭[1] 郑春萍[1] 

机构地区：[1]黑龙江大学化学化工学院,黑龙江哈尔滨150080

出　　处：《黑龙江大学自然科学学报》2001年第3期90-94,共5页Journal of Natural Science of Heilongjiang University

基　　金：黑龙江省自然科学基金资助项目(E9919)

摘　　要：以Ｂａ（ＯＡｃ）２，Ｌａ（ＯＡｃ）３；，Ｔｉ（ＯｎＢｕ）４为起始物，对溶胶－凝胶法制备的镧掺杂钛酸钡纳米多晶粉体ＬａｘＢａ１－ｘＴｉＯ３（Ｘ＝０．００，０．０５；０．１０，０．２０，０．３０）及陶瓷元件进行了多项特性表征，并利用正交设计对工艺参数进行优化：溶胶是在 ７０℃，ｐＨ＝３．８的醋酸介质中，由总浓度为 ０．７ｍｏｌ／Ｌ的起始物进行共溶水解而得；将溶胶在空温下自然浓缩和陈化而得湿凝胶；将湿凝胶置于恒温干燥箱中（５０℃／２４ ｈ）制得干凝胶；首先取少量干凝胶进行热分析（ＴＧ—ＤＴＧ），以确定大致的焙烧温度范围，然后取一部分干凝胶在此温度范围内的不同温度点上焙烧以制得一系列ＬａｘＢａ１－ｘＴｉＯ３粉体试样，对其进行ＥＤＳ、ＳＥＭ、ＦＴ－ＩＲ、ＸＲＤ测试，以比较各试样的金属组分含量、团粒形貌、晶相组成及原始晶粒尺寸．另一部分干凝胶则经研磨过筛之后等静压咸型（φ３．０×１．５ｍｍ），在不同温度和时间条件下烧结制得陶瓷传感元件，进行湿敏、气敏（包括酒敏）性能及显微结构的测试，从中获得了具有良好选择性和灵敏度的湿敏元件．The Sol - Gel processing has been refined to prepare lathanum doped barium titanate nanosized polycrystalline powders, LaxBa1-xTiO3(x=0.00, 0.05, 0.10, 0.20. 0.30), in the presence of Ba (OAc)2, La(OAc)3, Ti(OnBu)4 as starting materials with 0.7mol/L total concentration of precursor. The sol was obtained by cosolubilzed hydrosis of starting materials using HOAc as medium and catalyst with pH = 3.8. The wet gel was acquired by concentrating and ageing sol at room temperature. The wet-gel to dry-gel convertion was performed at 50 ℃ /24h in an electrical oven. First the dry gel was measured by TG - DTG and then was calcined at different temperatures (600℃, 700℃ , 800℃ , 900℃) to prepare nanocrystals. Dry get to - ceramic sensor conversion was achieved by isostaticly compacting and then sintering at 1350 - 1400 ℃ /1h. The final synthesis polycrystals and ceramic sensor were characterized by FT - IR spectroscopy, X - ray diffraction and Scanning electronic microscopy. The sensor of humidity sensibility showed good selectivity and linearlity. In the paper, the pattern recognition and artificial neural network were employed to optimized the processing parameters.

关 键 词：纳米多晶 工艺优化 陶瓷传感元件 镧修饰 钛酸钡 溶胶-凝胶法 

分 类 号：TQ132.35[化学工程—无机化工]