Ultrafine, nanometer-sized anatase particles were prepared by the hydrolysis of titanium isopropoxide. Their Raman spectra are discussed in view of the finite size effects. The crystallite size D estimated by the X-ray diffraction peaks (Scherrer method) was found to be correlated with the Raman peak width Gamma . The relationship could be expressed in the empirical equation, Gamma = Gamma0 + kD alpha with the scaling exponent alpha of 1.5. Because the anatase crystal spans a three-dimensional network, the result demonstrates that 2 X alpha is equal to the dimensionality of the sample. In addition, the anatase powders prepared by different hydrolysis schemes regressed into curves with different constant terms Gamma0 and k. The amount of or ganic residue was mainly affected by the hydrolysis scheme, and the organic residue caused the formation of defects in the crystalline particle by the following heat treatment. Therefore, it is obvious that the variation in Gamma0 and k has a close relation to the defect density of the crystalline particles. The defect densities were estimated by using the correlation between the X-ray diffraction and the Raman data.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription