Structural and optical characterization of BaTiO₃ thin films prepared by metal-organic deposition from barium 2-ethylhexanoate and titanium dimethoxy dineodecanoate

Abstract

Single phase BaTi03 thin films were prepared by metal-organic deposition (MOD) using barium 2-ethylhexanoate and titanium dimethoxy dineodecanoate as the metal-organic precursors. A series of experiments was conducted on the metal-organic spin-coated films and their correspondingly annealed samples by employing experimental techniques ranging from thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscopy (SEM), to various optical property characterization methods. A better understanding has been achieved regarding the metal-organic decomposition mechanism, the solid-state BaTi03 film formation and crystallization process, as well as the relationship between the structure and the optical properties of the prepared films. The conclusions of our experiments are as follows: Upon annealing the barium 2-ethylhexanoate spin-coated films, barium carbonate (BaC03) is formed at a relatively low temperature of 300 °C, and at an annealing temperature around 700 °C forms the barium peroxymonocarbonate (BaCO4). Upon annealing the titanium dimethoxy dineodecanoate spin-coated films, anatase is first formed at a low annealing temperature about 400 °C and transforms to rutile phase around an annealing temperature of 800 °C. Upon annealing the spin-coated films from the equimolar mixture of barium 2-ethylhexanoate and titanium dimethoxy dineodecanoate formulations, BaTi03 is formed around an annealing temperature of 600 °C via solid-state reaction between BaCO3 and TiO2 (anatase). The structure of MOD prepared BaTiO3 films has several specific features: instead of the columnar structure in physical vapor deposited (PVD) films, the crystal grains in granular shape are characteristic of MOD films, and the crystallites are much larger near the surface of the film than near the substrates. Optical properties of the prepared BaTi03 films have been reported. Optical characterization shows that the scattering losses contribute dominantly to the total optical losses. The relationship between the structure and the optical properties of the prepared films has also been discussed.

Size controlled synthesis of highly dispersed anatase/rutile nanoparticles with photocatalytic activity toward salicylic acid degradation

“…Regarding the two titania phases present in all the samples, according to the literature, 25 the formation of rutile and/or anatase from the decomposition of free Ti(OnPr) 2 (hex) 2 depends on the temperature of thermal treatment: at 773 K, titania composed of 38% rutile is obtained; at 873 K the amount of rutile increases to 43%; and at 973 K pure rutile is obtained. The decomposition of another TiO 2 precursor, titanium di-(methoxy)-di-(neodecanoate), as thin films, also presented a behavior dependent on the temperature: 26 below 813 K, pure anatase film is obtained; at around 943 K both anatase and rutile were identified; and at around 1093 K, a complete phase transition occurs and rutile is the only TiO 2 phase obtained. Therefore, the formation of both rutile and anatase in SBA-15 samples impregnated with Ti(OnPr) 2 (hex) 2 and thermally treated at 1023 K is consistent with the literature, considering that the thermal decomposition of the titanium metallo-organic precursor is occurring in the confined ambient SBA-15 pores.…”

Link-up of 90° domain boundaries with interface dislocations in BaTiO3/LaAlO3

“…Epitaxial growth of barium titanate (BaTiO 3 ͒ thin film has attracted much attention because of its potential application in microelectronics and integrated photonics. 1 The filmsubstrate interfacial structure plays an important role in determining the quality of the film. Misfit dislocations are usually produced at the interface to partially relieve the strain due to lattice mismatch.…”

Polymer‐assisted deposition of perovskite dielectric oxide thin films

“…This results in an ageing effect of the gel which increases the difficulty in controlling the structural and physical properties of the final production. Another CSD technique, metal-organic deposition, using the carboxylate-carboxylic acids system in precursor solution preparation, can overcome the issue of the ageing effect in hydrolysis [13][14][15]. However, the solvents used in this technique are generally organic solvents, which will increase the cost of the whole fabrication process and may cause possible environmental pollution.…”