Effects of silicon doping on phase transformation mechanism of titanium dioxide

• Published in: Cailiao gongcheng
• Main Authors: WU Sheng-cai, LUO Xian, LONG Yong-fu, ZHANG Lu, XU Ben-jun, HUANG Run
• Format: Article
• Language: Chinese
• Published: Journal of Materials Engineering 2020-11-01
• Subjects: doping; titanium dioxide; solid solution; phase transformation; silicon dioxide
• Online Access: http://jme.biam.ac.cn/CN/10.11868/j.issn.1001-4381.2019.000996

Under the physical mixed doping of different amounts of SiO₂, high temperature <i>in-situ</i> XRD, TEM, XPS and Rietveld full spectrum fitting were used to analyze the change rule of chemical bond and the influence of silicon on the transformation mechanism of anatase to rutile (A→R) TiO₂.The results show that the influence mechanism is controlled by distortion energy and crystal nucleus formation. When the doping amount of SiO₂ is less than 7.5% (mass fraction, the same as below), the phase transition is inhibited. At this point, Si⁴⁺ replaces Ti⁴⁺ ions in the titanium dioxide lattice, resulting in distortion and inhibiting the A→R transformation of titanium dioxide. When the doping amount of SiO₂ is greater than 7.5%, it is the promotion effect. At this time, the excess SiO₂ acts as the crystal nucleus of rutile, thus promoting the transformation of A→R.