Microstructure and dielectric properties of (Ba,Sr)TiO₃ thin film produced by the polymeric precursor method

Abstract

LiNbO 3 thin films were grown on (0001) sapphire substrates by a chemical route, using the polymeric precursor method. The overall process consists of preparing a coating solution from the Pechini process, based on metallic citrate polymerization. The precursor films, deposited by dip coating, are then heat treated to eliminate the organic material and to synthesize the phase. In this work, we studied the influence of the heat treatment on the structural and optical properties of single-layered films. Two routes were also investigated to increase the film thickness: increasing the viscosity of the coating solution and/or increasing the number of successively deposited layers. The x-ray diffraction -2 scans revealed the c-axis orientation of the single-and multilayered films and showed that efficient crystallization can be obtained at temperatures as low as 400°C. The phi-scan diffraction evidenced the epitaxial growth with two in-plane variants. A microstructural study revealed that the films were crack free, homogeneous, and relatively dense. Finally, the investigation of the optical properties (optical transmittance and refractive index) confirmed the good quality of the films. These results indicate that the polymeric precursor method is a promising process to develop lithium niobate waveguides.

Characterization of physical and electrical properties of BaTiO3 films deposited on p-Si by modified polymeric precursors

“…It is found to be E g ϭ 3.95 eV in very good agreement with previously published results. 2,3,6,14,17 The magnitude of the leakage current varies from 10 Ϫ9 A to 10 Ϫ6 A, depending on the applied voltage.…”

“…[3][4][5][6][7][8] Many methods, such as sputtering, 9 laser ablation, 10 metalorganic chemical vapor deposition (MOCVD), 11 and sol-gel 12 techniques, have been used to grow thin films; however, most of these methods are expensive and require complex equipment. The polymeric precursor method [13][14][15][16] is a chemical technique that offers several advantages, such as low cost, good compositional homogeneity, high purity, relatively low processing temperatures, and the ability to coat large substrate areas. In this technique, the desired metal cations are chelated in a solution using a hydroxycarboxylic acid as the chelating agent.…”

Structural phase evolution of strontium-doped lead titanate thin films prepared by the soft chemical technique

“…Details of the preparation method can be found in the literature. 16,17 The polymeric precursor solution was spin-coated on substrates [Pt (140 nm)/Ti (10 nm)/SiO 2 (1000 nm)/Si] by a commercial spinner operating at 6000 rev/min for 20 s (spin-coater KW-4B, Chemat Technology, Northridge, CA), via a syringe filter to avoid particulate contamination. After spinning, the films were kept in ambient air at 150°C on a hot plate for 20 min to remove residual solvents.…”

Photoluminescence at room temperature in amorphous SrTiO3 thin films obtained by chemical solution deposition

“…This paper reports on measurements of broad, intense photoluminescence observed at room temperature in SrTiO 3 amorphous thin films prepared at low temperatures and obtained by the polymeric precursor method [13][14][15].…”