掺镧改性钛酸钡纳米多晶粉体的制备和表征

无机材料学报

掺镧改性钛酸钡纳米多晶粉体的制备和表征

王智民; 韩基新; 刘静波

黑龙江大学化学化工学院哈尔滨 150080

收稿日期:2001-09-17 修回日期:2001-11-22 出版日期:2002-09-20 网络出版日期:2002-09-20

Preparation and Characterization of La³⁺-doped Barium Titanate Nanosize Polycrystalline Powders

WANG Zhi-Min; HAN Ji-Xin; LIU Jing-Bo

College of Chemistry and Chemical Engineering; Heilongjiang University; Harbin 150080; China

Received:2001-09-17 Revised:2001-11-22 Published:2002-09-20 Online:2002-09-20

摘要/Abstract

摘要： 以La（OAc）₃,Ba（OAc）₂,Ti（On-Bu）₄为起始物,采用共溶-水凝胶法制备掺镧改性钛酸钡纳米多晶粉体La_xBa_1-xTiO₃（x=0.00,005,0.10,0.20,0.30）,利用正交试验对制备溶胶的主要工艺进行优化:溶胶是由总浓度为0.7mol/L的起始物逐步滴入蒸馏水进行共溶水解而得,其介质为氨水调节的pH=3.8和70℃的醋酸.将溶胶陈化和浓缩而得湿凝胶,干凝胶是将湿凝胶在烘箱中经50℃/24h处理而得.对干凝胶及其焙烧粉体进行了七项特性表征:首先取少量干凝胶进行TG-DTG和FT-IR测试,以确定焙烧温度范围和历程;然后另取一部分干凝胶在该温度范围内的不同温度点上焙烧,以便制得系列粉体试样,对其进行FT-IR、XRD、SEM、EDS、TEM及LRS表征,以比较各试样的晶相组成、原始晶粒尺寸、晶格常数及其四方相畸变度δ（即晶轴比c/α）、团粒形貌及微区金属元素含量等并从中优选工艺,探讨共溶-水凝胶过程及掺镧改性机理等.

关键词: 掺镧改性钛酸钡（La_xBa_1-xTiO）₃, 共溶-水凝胶法, 纳米多晶粉体, 显微结构表征

Abstract: Nanosize polycrystalline powders of lanthanum doped barium titanate were prepared by the cosolubilized-
hydrous gel process using titanium butoxide and lanthanum acetate as well as barium acetate with 0.7mol/L total concentration of precursor. The sol was
obtained by cosolubilized hydrosis of starting materials using HOAc as medium and catalyst with pH=3.8. The wet-gel was acquired by concentrating and aging
sol at room temperature. The wet-gel to dry-gel conversion was performed at 50℃/24h in an electrical oven. The TG-DTG measurement of dry-gel
was carried out to determine the appropriate temperature range of calcination. Then a series of polycrystal powders were prepared by calcining dry-gel at different points of above temperature range. Powder samples were characterized detailedly to confirm
the phase formation, crystalline size, grain morphology, elemental composition and the fine structure by FT-IR, XRD, SEM, EDS, TEM and LRS. So that opitimizing
800℃/2h as the suitable condition for calcination of dry-gel to prepare nanosize polycrystal powders La_xBa_1-xTiO ₃(x=0.00, 005,
0.10, 0.20, 0.30).

Key words: modification of La³⁺-doped barium titanate （La_xBa_1-x cosolubilized hydrous-gel process, nanosize polycrystal powders, microstructure characterizations

中图分类号:

TM283

王智民,韩基新,刘静波. 掺镧改性钛酸钡纳米多晶粉体的制备和表征[J]. 无机材料学报.

WANG Zhi-Min,HAN Ji-Xin,LIU Jing-Bo. Preparation and Characterization of La³⁺-doped Barium Titanate Nanosize Polycrystalline Powders[J]. Journal of Inorganic Materials.