The behaviors of anatase and TiO2(B) phase coexisting nanosheets under high pressure

Abstract

Abstract High pressure behaviors of anatase TiO 2 and TiO 2 (B) coexisting nanosheets were investigated using in situ synchrotron X-ray diffraction and Raman Spectroscopy. The X-ray diffraction revealed that upon compression an α-PbO 2 phase appeared at 11.4 GPa, and then the baddeleyite phase appeared at 23.6 GPa. Upon decompression the anatase phase still existed obviously and TiO 2 (B) phase almost cannot be observed. The Raman spectrum at ambient pressure presented the typical curve of anatase TiO 2 , however the pressure dependence for compression and decompression did not show the common phase transion from anatase to α-PbO 2 or to baddeleyite. This is different from high pressure behaviors of other TiO 2 nanostructures and could be attributed to the existence of small amount of TiO 2 (B) at the starting materials. The pressure relationship of the Raman frequencies shift slope indicated the coexistence nanosheet has high incompressibility compared with other TiO 2 nanomaterials and corresponding bulks.