Structural and optical properties of Ba(Cox,Ti1−x)O3 thin films fabricatedby sol-gel process

Abstract

Ba ( Co x , Ti 1 − x ) O 3 thin films were prepared on fused quartz substrate by a sol-gel method. The results of x-ray diffraction showed that the films are perovskite phase and the change of lattice constant caused by different Co concentration is undetectable. Optical transmittance measurement indicated that Co doping has effect on the energy band structure. The energy gap of Ba(Cox,Ti1−x)O3 decreased linearly with the increase of Co concentration. It is inferred that the energy level of conduction bands decline with the Co content increasing. This result is similar to the phenomena found in binary semiconductor where the band gap decreases with the increasing of average atomic number.

Composition dependence of dielectric function in ferroelectric BaCoxTi1−xO3 films grown on quartz substrates by transmittance spectra

“…4 On the other hand, optimal cation doping ͑Ti 4+ ͒ is a widely accepted approach to tailor the physical properties, such as transition temperature, ferroelectric characteristics, and dielectric properties. Recently, perovskite ferroelectric film materials have received much attention in view of their wide applications in dynamic random access memories, electro-optic switches, pyroelectric detectors, optical modulators, and mixers.…”

Investigation of microstructural and optical properties of (K,Ba)(Ni,Nb)O3−δ thin films fabricated by pulsed laser deposition

“…Ferroelectric thin films have great applications in electro-optic devices, nonvolatile memory, and dynamic access memory [1,2]. Various methods, both vacuum-based and non-vacuum based techniques, such as pulse laser deposition (PLD), metalorganic chemical-vapor deposition, sol-gel processing, and streaming process for electrodeless electrochemical deposition (SPEED), have been employed in fabricating epitaxial and polycrystalline films [3][4][5][6].…”

Pb-free semiconductor ferroelectrics: A theoretical study of Pd-substitutedBa(Ti1−xCex)O

“…13 However, when Co is substituted, the band gap decreases with increasing Co concentration ͑x = 0.01-0.10͒. 14 In a previous study, we explored the effects of substituting another transition metal, Pd, into BaCeO 3 and found that the presence of Pd stabilized by an O-vacancy decreased the band gap significantly by creating a stable square-pyramidal Pd complex. 15,16 Although BaCe 1−x Pd x O 3 is not ferroelectric, solid solutions of Ba͑Ti 1−x Ce x ͒O 3 have been synthesized and are reported to demonstrate ferroelectric responses.…”