[Study on nanophase anatase-rutile transition with Raman spectrum].

The nanophase anatase of different size (the average is 40 nm) was synthesized with chemical precipitation method. Transition from nanophase and microphase anatase to rutile were investigated with Raman spectrum. The result indicated that rutile characteristic peak (446 cm-1) appeared after 1 h heat preservation at 900 degrees C for microphase anatase, raising the temperature characteristic peak intensity of rutile (446,610 and 231 cm-1) continued to increase and characteristic peak of anatase (639,515 and 397 cm-1) decreased bit by bit. After 1 h heat preservation at 1,100 degrees C anatase transformed into rutile. While the nanophase anatase transited into rutile entirely after 1 h heat preservation at 900 degrees C, which is about 200 degrees C lower than microphase anatase to rutile transition temperature.