TiO_2纳米粒子热处理过程相变原因研究  

Study on phase transition of nano-size TiO_2 during the heat treatment

作　　者：付姚[1] 曹望和[1] 夏天[1] 周立新[1] 田莹[1] 

机构地区：[1]大连海事大学光电子技术研究所,辽宁大连116026

出　　处：《功能材料》2005年第2期250-251,255,共3页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(60274040)

摘　　要：通过差热 热重分析(TG DTA)和 X射线衍射分析(XRD)对热处理过程中 TiO2 纳米粒子相变过程进行了研究。结果表明,在热处理过程中, 纯锐钛矿相TiO2 纳米粒子的相变温度与粉体粒径的大小有关,当粉体粒径<21nm时,金红石相的标准自由能大于锐钛矿相,粉体不会发生相变。当粉体粒径增大到21nm以上时,情况相反,粉体可能发生相变,表现出明显的尺寸效应。In this paper, the process of phase transition of nano-size TiO2 during the heat treatment was studied by means of TG-DTA and XRD analysis. The results showed that phase transition temperature of nano-size pure anatase TiO2 was relative to the particle-size of the powder. The standard free energy of rutile is higher than the one of anatase when the particle-size was no more than 21 nm, so that the phase transition of powder can not occur. As the increment of particle-size over 21 nm, however, the situation is just reverse and the phase transition may be able to happen. These phenomena show an obvious effect of dimension.

关 键 词：TIO2 热处理 相变 表面自由能 

分 类 号：O64[理学—物理化学]