Optical properties of PbTiO3, PbZrxTi1−xO3, and PbZrO3 films deposited by metalorganic chemical vapor on SrTiO3

Abstract

Epitaxial PbZrxTi1−xO3 (PZT) films have been prepared by metalorganic chemical vapor deposition on SrTiO3 substrates. Two sets of films of thicknesses 50–100 and 700–1400 nm, containing 0%, 40%, 60%, and 100% Zr, were prepared and investigated. The refractive index n was determined by ellipsometry for the thin films and by reflectivity for the thicker films. Results were obtained over the energy range from 1.55 to 3.72 eV, and with a Cauchy-fit extrapolation down to 0.62 eV. The refractive-index curves show a systematic variation with composition. For all compositions, n is close to 3.2 at 3.72 eV (333 nm), while at 1.55 eV (800 nm) n is 2.35 for PZ (x=1) and 2.61 for PT (x=0). In agreement with previous results we find that the optical band gap is essentially independent of composition for PZT. We obtained 3.6±0.1 eV. The n(E) results were analyzed by a Wemple–DiDomenico dispersion analysis, yielding results for the dispersion region in the ultraviolet. Unlike the band gap, which is insensitive to composition in PZT, the dispersion energy Ed decreases from PT to PZ in the same fashion as the refractive index in the transparent region.

Effect of thickness on dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films

“…42,43 The calculated values of n were in the range of 2.17-2.43 and 2.11-2.34 for 200 and 400 nm respectively, similar to the values found for PZT thin films. [43][44][45][46] The computed values of k were found in the range of 0.04-0.053 and 0.015-0.018 for 200 and 400 nm, respectively, which are comparable with the k value reported earlier for PZT thin films. 43,45,47 The n-values for both films decrease exponentially as the wavelength increases, which is consistent with previously reported behavior of PZT thin films.…”

Thermal induced changes of lead zirconium titanate films and their consequences for liquid crystal devices applications

“…Such values are consistent with the literature data that assign the lowest value, obtained from each sample, to the presence of the pyrochlore phase and the highest to the presence of ferroelectric perovskite phase, of the PZT with the same stoichiometric ratio (Zr=0.53, Ti=0.47) [20,21,[26][27][28][29]. It means, that when the annealing temperature is lower than 600°C, the pyrochlore ( eV E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 F o r P e e r R e v i e w O n l y 10 while for negatives ones they do not switch.…”

Wide bandgap tunability in complex transition metal oxides by site-specific substitution

“…Other ferroelectrics have similar rigid bandgaps. For example, Pb(Zr,Ti)O 3 shows an experimental bandgap spectrum < 0.2 eV by doping 26,27 . Thus, we have accomplished wide bandgap tunability (~1 eV), which is about five times greater than what has been reported so far from oxide ferroelectrics.…”