Shock synthesis and characterization of titanium dioxide with α-PbO 2 structure

The phase transformation behavior of anatase and rutile titanium dioxide with particle sizes of 60 nm and 150 nm under shock compression have been investigated. To increase the shock pressure and reduce the shock temperature, copper powder and a small amount of paraffin were mixed with the TiO powder. The shock recovered samples were characterized by x-ray diffraction, Raman spectroscopy, and transmission electron microscope. The results indicate that both anatase and rutile TiO can transform to α-PbO phase TiO through shock-induced phase transition. The transformation rate of α-PbO phase TiO for anatase TiO under shock compression is 100% and pure α-PbO phase TiO can be obtained, while the transformation rate for rutile TiO is over 90%. The influence of the particle size on the yield of α-PbO phase TiO is not noticeable. The thermal stability of the recovered pure α-PbO phase TiO was characterized by high temperature x-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The results show that α-PbO phase TiO transforms to rutile TiO when heated to temperature higher than 560 °C. The mechanisms of the phase transition of TiO under shock compression are discussed.