Time dependent property of microstructure changing of TiO_xH_y during anneal treatment

Abstract

The hydroxile compound, TiO_xH_y was the material with the amorphous TiO₂ cluster terminated by the OH group. The structure of this material transforms to the crystalline form of the anatase type of TiO₂ by the anneal treatment. This study focuses on the time dependent property of microstructural changing of TiO_xH_y during the anneal treatment. The TiO_xH_y film was deposited using an atmospheric chemical-vapor-deposition reactor with tetraisopropyl titanate. The deposited films were annealed in the furnace heated at 250°C. The structure of this material transforms to the crystalline form of the anatase type of TiO₂ for the 36 hours. The average cluster size of the sample was determined as 5 nm and 36 nm, using the result of Raman spectroscopy, for annealing time of 24 hours and 48 hours, respectively. The cluster size suddenly increases to 5∼36 nm when the structure of the material changes from amorphous to crystalline states detected by Raman spectroscopy and X-ray diffractometry, respectively.