Spectroellipsometric study of sol-gel derived potassium sodium strontium barium niobate films

Chee Leung Mak, B. Lai, K. H. Wong, C. L. Choy, D. Mo, Y. L. Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

13 Citations (Scopus)

Abstract

Spectroscopic ellipsometry (SE) was used to characterize the sol-gel derived (K0.5Na0.5)0.4(Sr0.6Ba0.4)0.8Nb2O6, (KNSBN) thin films as a function of sol concentration. In the analysis of the measured SE spectra, a modified double-layer Forouhi-Bloomer model was adopted to represent the optical properties of the KNSBN films. In this model, the films were assumed to consist of two layers - a bottom bulk KNSBN layer and a surface layer that composed of bulk KNSBN as well as void. Good agreement was obtained between the measured spectra and the model calculations in the chosen spectral region. Effective medium approximation theory was used to evaluate the effective refractive index for the surface layer. The results of SE have been correlated with atomic force microscopy measurements of surface roughness. Our analyses have shown that the surface layer had a lower refractive index than the bottom one. In addition, the refractive index and the surface roughness of the KNSBN films increase with the sol concentration.
Original languageEnglish
Pages (from-to)4491-4496
Number of pages6
JournalJournal of Applied Physics
Volume89
Issue number8
DOIs
Publication statusPublished - 15 Apr 2001

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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