摘要
通过加入添加剂经水热合成法制备了单相无硬团聚的 10～ 2 0nm锰锌铁氧体纳米晶 ,运用TEM ,XRD等进行了表征。引用热力学方法原理及相变理论分析了水热合成机理。以简化的数学模型讨论了晶体生长过程 ,晶体生长过程可分为两个阶段 ,分别满足以下动力学方程 :D =1.2 9× 10 -9exp(-Q1/RT)t+ 8.0 4× 10 -9 t<t0D =5 .86× 10 -9exp(-Q2 /RT)t+ 10 .93× 10 -9 t>t0分别求出了晶体生长不同阶段的激活能 ,Q1=3 6.17kJ·mol-1,Q2 =5 0 .3 0kJ·mol-1。t0 与晶化温度有关 ,t0 =2 .89/[1.2 9exp(-Q1/RT) -5 .86exp(-Q2 /RT) ]。
Single phase aggregate-free nanocrystal MnZn ferrite particles with a size of 10～20nm were perapared via hydrothermal method by additive, which were characterized by TEM and XRD. The mechanism of hydrothermal process was studied by thermodynamics analysis and phase transformation theory. Crystal growth process was discussed with a simplified mathematics model. Two kinetics equations were established by which crystal growth process was divided into two steps.D =1.29×10 -9 exp(- Q 1/RT)t +8.04×10 -9 t<t 0 D =5.86×10 -9 exp(- Q 2/RT)t +10.93×10 -9 t>t 0The crystal growth activation energy were obtained respectively, Q 1=36.17kJ·mol -1 , Q 2=50.30kJ·mol -1 , t 0 was related to crystallization temperature T,t 0=2.89/[1.29exp(- Q 1/RT) -5.86exp(- Q 2/RT)].
出处
《功能材料》
EI
CAS
CSCD
北大核心
2001年第1期27-29,共3页
Journal of Functional Materials
关键词
水热法
添加剂
锰锌铁氧体纳米晶
热动力学
制备
hydrothermal method
additive
nanocrystal MnZn ferrite particle
thermal-kinetics
