论文部分内容阅读
拉曼光谱用于研究二氧化钛材料的相变和声子限制效应。化学溶液方法制备了TiO2纳米晶材料。其平均粒度为 6 8- 2 7 9nm。最低频率 1 5 2cm- 1 Eg 模随粒度减小出现蓝移和加宽。在声子限制模型下 ,理论上对不同粒度的TiO2 纳米晶 (6 8,1 0 3和 2 7 9nm)的频移和线宽进行计算 ,结果与实验吻合得很好。研究了TiO2 纳米晶锐钛矿 -金红石相变 ,其相变温度为 6 5 0 - 6 90℃ ,比体块TiO2 的相变温度 1 0 0 0℃低 ,表明了相变的尺寸效应
Raman spectroscopy is used to study the phase transition and phonon confinement effects of TiO2 materials. TiO2 nanocrystalline materials were prepared by chemical solution method. The average particle size is 6 8- 2 7 9 nm. The lowest frequency of 1 5 2cm-1 Eg mode decreases and the blue shift and broadening appear. Under the phonon confinement model, the frequency shift and linewidth of TiO2 nanocrystals with different particle sizes (6 8, 103 and 279 nm) are theoretically calculated. The results are in good agreement with the experiment. The anatase-rutile phase transition of TiO2 nanocrystals was studied. The phase transformation temperature was between 650 and 690 ℃, which was lower than the phase transition temperature of the bulk TiO2 at 100 ℃, indicating the size effect of phase transition