高温原位XRD法研究含硅杂质TiO_2的煅烧相变机理

Phase Transition Mechanism of Calcined Titanium Dioxide Containing Silicon by High Temperature In-Situ X-ray Diffraction

为了揭示Si杂质元素对TiO_2相变机理的影响,通过TiCl_4水解法制得Si摩尔分数为10%的H_2TiO_3和H_4SiO_4的金红石中间体,用DTA-DTG,XRD研究TiO_2在Si元素作用下的高温相变过程。结果发现,掺杂Si(10%)元素的TiO_2是在650℃开始由无定形结构转变为锐钛矿相,1 000℃时由锐钛矿相转变为金红石相。结果表明:与纯的TiO_2相变温度相比,掺杂Si元素抑制了TiO_2由无定形到锐钛矿相及锐钛矿相到金红石相的转变温度;同时发现随着高温时间的增加TiO_2同种晶型结晶性变化规律。

In order to reveal the influence of Si impurity elements on the phase transformation mechanism of titanium dioxide, rutile intermediates of H2TiO3 and H4SiO4 doped with Si(10%) were prepared by TiCl4 hydrolysis method. The high temperature phase transition of TiO2 under the effect of doped-Si was studied by DTA-DTG and XRD. As a result, it was found that the Si(10%) doped TiO2 was transformed from an amorphous structure to an anatase phase at 650 ℃, and changed from an anatase to a rutile phase at 1 000 ℃. The results show that compared with the pure TiO2 phase transition temperature, the doping of Si inhibits the transformation temperature from amorphous to anatase and anatase to rutile. At the same time, it was found that with the increase of the high temperature time, the crystallinity of the same crystal form of titanium dioxide changes.