Abstract

AbstractWe calculated and analyzed the effects of temperature and crystallite size on the Raman properties of nanocrystalline anatase TiO2 by using the related models mentioned previously [Tang and Herman, Phys. Rev. B 43, 2299 (1991); Richter et al., Solid State Commun. 39, 625 (1981)]. The temperature dependence of the Raman spectra of two different crystallite sizes of anatase TiO2 were obtained. Careful measurements of the frequency shifts of Raman modes were carried out at different temperatures. Through fitting the experimental data, pure‐volume and the pure‐temperature contributions to the frequency shifts of the lowest‐ and highest‐frequency Eg modes, respectively, have been calculated. The results indicated that strongly intrinsic anharmonicity arising from optical‐phonon couplings was the origin of hardening upon increasing temperature for the lowest‐frequency Raman mode. The phonon‐confinement effect on this mode was analyzed and anharmonic shifts of optical phonons with two different kinds of crystallite sizes were also compared. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.