Structural, ferroelectric and optical properties of Bi2VO5.5 thin films deposited on platinized silicon {(100) Pt/TiO2/SiO2/Si} substrates

• Published in: Applied physics. A, Materials science & processing Vol. 91; no. 4; pp. 693 - 699
• Main Authors: Kumari, N., Krupanidhi, S.B., Varma, K.B.R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2008; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Physics and Astronomy; Processes; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and Interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin Films; Spectroscopic Ellipsometry; Optical Constant; Atomic Force Microscopy; Dielectric Function; Complex Dielectric Function; Atomic force microscopy; Refractive index; Surface morphology; Bismuth Vanadates; Roughness; Pulsed laser deposition; Extinction index; Thin films; Thickness; Dielectric function; Ferroelectricity; Effective medium model; Optical constants
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-008-4509-z

Bismuth vanadate (Bi 2 VO 5.5 , BVO) thin films have been deposited by a pulsed laser ablation technique on platinized silicon substrates. The surface morphology of the BVO thin films has been studied by atomic force microscopy (AFM). The optical properties of the BVO thin films were investigated using spectroscopic ellipsometric measurements in the 300–820 nm wavelength range. The refractive index (n), extinction coefficient (k) and thickness of the BVO thin films have been obtained by fitting the ellipsometric experimental data in a four-phase model (air/BVO rough /BVO/Pt). The values of the optical constants n and k that were determined through multilayer analysis at 600 nm were 2.31 and 0.056, respectively. For fitting the ellipsometric data and to interpret the optical constants, the unknown dielectric function of the BVO films was constructed using a Lorentz model. The roughness of the films was modeled in the Brugmann effective medium approximation and the results were compared with the AFM observations.