Infrared optical properties of PbTiO3 ferroelectric thin films
Abstract
Infrared optical properties of lead titanate (PbTiO3) thin films grown on Pt/Ti/SiO2/Si substrates are studied by infrared spectroscopic ellipsometry (IRSE) in the spectral range of 2.5-12.6 µm. The refractive index and extinction coefficient of PbTiO3 thin films are determined by fitting the IRSE data using a derived classical dielectric function formula. The refractive index decreases; on the contrary, the extinction coefficient increases as the wavelength increases. The absorption coefficient is greater than 1000 cm-1 for wavelengths over 11.7 µm, but very small and less than 100 cm-1 for wavelengths under 4.8 µm. The effective static ionic charge has also been derived, which is smaller than it would be in a purely ionic material for PbTiO3 thin films.
- Publication:
-
Journal of Physics D Applied Physics
- Pub Date:
- February 2002
- DOI:
- 10.1088/0022-3727/35/3/313
- Bibcode:
- 2002JPhD...35..246H