OPTICAL PROPERTIES OF ANATASE TiO2 UNDER THE HIGH PRESSURE

Optical absorption, luminescence and Raman spectra were measured for anatase TiO 2 under high pressures. The pressure dependence of Raman frequencies is determined. The absorption edge of anatase shifts to higher energy side with increasing pressure and the edge jumps abruptly to lower energy side on the phase transition. A broad luminescence band of anatase shifts also to higher energy side with increasing pressure. These experimental results reveal that the pressure-induced phase transition from anatase to high-pressure phase arises in the range of 4.0-4.6 GPa.