| Sodium niobate NaNbO3 thin films were deposited by the pulsed laser ablation (PLD) technique on Si/SiO2/Ti/Pt/SrRuO3 and Si/SrRuO3 substrates. The structural and optical investigations were performed by X-Ray, micro Raman, ellipsometry and atomic force microscopy (AFM). The Raman spectra of NN have been studied at temperatures from 80 up to 743K at frequencies 200 - 1100 cm-1. Optical properties were studied at photon energies 1.23 - 4.85 eV. Some Raman modes show lower frequencies, and the refractive index is higher for the NN films with smaller grains. The observed difference is discussed in terms of possible size induced phase transformation and/or grain boundary effects. |
full paper (pdf, 336 Kb)