Low-temperature synthesis of barium titanate thin films by nanoparticles electrophoretic deposition

Abstract

The nanoparticles electrophoretic deposition (EPD) of barium titanate (BaTiO 3 or BTO) thin films was investigated. BTO nanocrystallites in a pseudocubic perovskite phase with an average particle size of about 10 nm were synthesized at a low temperature of 90°C by a highconcentration sol-gel process. By using a mixed solvent of 2-methoxyethanol and acetylacetone as dispersing medium, transparent and well-dispersed BTO nanocrystallites suspensions within the concentration range of 0.0125 to 0.20 mol/l was successfully prepared for nanoparticles EPD. A uniform microstructure and a smooth surface were observed on the deposited films. The film thickness of the deposited films increased rapidly with increasing EPD time in the initial period of EPD, and thereafter gradually increased to a limited thickness. With increasing applied EPD voltage, the limited film thickness increased. A near linear relation between the film thickness of films and the concentration of suspensions was observed under the same EPD conditions. The microstructures of the deposited BTO thin films were investigated.

Moldless micropatterning of BaTiO3 nanoparticles via electrophoretic deposition: A simple and feasible method

“…For example, Xiong et al [10] and Winkleman et al [11] attested that the micrometer and nanometer scaled micropatterns were electrophoretically achieved by selective deposition of the spherical latex particles in the predesigned trenches, respectively. In our lab, Dr. Wu et al [3,4] also proved previously that electron beam lithography and EPD could be combined and employed for selective deposition of nanoscale BaTiO 3 micropatterns with the microarrays of lines, grids, and dots. On the other hand, it has been demonstrated that an important challenge in micromanufacturing is the direct growth or assembly of nanoelements over macroscopic length scales [12].…”

“…In particular, the technique for fabricating patterned colloidal microstructures from particle suspensions has the promising purposes in the materials processing [2]. Very recently, a great deal of attention has been focused on the fabrication of patterned electroceramic materials due to the increasing demands for integrating them into microelectronic devices, and their potential applications as sensing, optical, and photonic band-gap materials [3,4]. Specially, deposition of micropatterned barium titanate (BaTiO 3 ) films onto metal electrodes has attracted significant interest for its conspicuous technological applications in both the electronic and optical component industries.…”

“…Various strategies, basing on gravity-sedimentation, electrostatic interaction, nanosphere lithography, electrophoresis, have been explored to fabricate BaTiO 3 and other colloidal particle micropatterns on a solid substrate [4][5][6]. Among these techniques, the electrophoretic deposition (EPD) process has been demonstrated to be a promising method for its extensive employments not only in ceramic film forming but also in particle alignment for microscale ceramic or polymer spherical particles on planar or patterned substrates [1,3,7]. Furthermore, lithography (including electron beam lithography and photolithography) has been utilized for fabricating very high resolution resist molds with nano-or mico-scale structures [8].…”