Papers by Keyword: Precursor Solution

Abstract: Using (NH₄)₂TiF₆, Bi(NO₃)₃•5H₂O and H₃BO₃ as raw materials, Bi₄Ti₃O₁₂ thin films were synthesized with liquid phase self-assembled monolayers on the glass substrate. The different precursor solution concentrations and acid contents had the effects on the physical phase and morphology of Bi₄Ti₃O₁₂ thin films. The Bi₄Ti₃O₁₂ thin films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results indicate that the precursor solution with 10.0 mmol/L concentration was prepared by 3:4:9 molar ratio of (NH₄)₂TiF₆: Bi(NO₃)₃•5H₂O: H₃BO₃ and 6.0 ml acid content, depositing at 50°C for 20h, and heat treating at 590°C for 2h. The as-prepared thin films are well-crystal. The surface is even and dense. The formation mechanism of the Bi₄Ti₃O₁₂ thin films is as follows: [TiF_6-n(OH)_n]^2- complex ions are formed in the (NH₄)₂TiF₆ aqueous solution. Then H₃BO₃ continually consumed F^- ions of the solution, which made the amounts of [TiF_6-n(OH)_n]^2- ions increase gradually. Under the induction of the electrostatic force, Bi³⁺ ions and [TiF_6-n(OH)_n]^2- ions would grow naturally on the substrate surface in the form of Bi₂[TiF_6-n(OH)_n]₃ or Bi₂[TiF_6-nO_m/2(OH)_n-m]₃. The samples lost the bound water after the heat treatment and finally the Bi₄Ti₃O₁₂ thin films with pure phase were obtained.

Abstract: In this paper, electrospinning method was adopted to prepare tin oxide nanofibers membrane with three kinds of novel precursor solution PVP/C12H24O4Sn, PVP/ C4H10OSn and PVP/SnCl4. The morphology, surface element, thermal analysis and crystal structure of the fibers membrane were investigated by SEM, EDS, TG-DTA and XRD. The results showed that the organic/inorganic hybrid nanofibers with an average diameter of 300～700 nm can be obtained by electrospinning. But after calcined at 600°C, the loose and porous tin oxide nanofibers membrane with an average diameter of 100～250 nm can be obtained only by using PVP/SnCl4 as preceusor solution, moreover, it showed good fiber forming property. From XRD spectra, it was found that the rutile structure tin oxide finally obtained without other crystalline forms.

Abstract: The HfO2 films were prepared on the ITO/polyimide substrate using alkoxy-derived precursor solutions at low temperature. The HfO2 films prepared by UV-assisted process using the precursor solution modified with diethanolamine had smooth surface and RMS roughness values of HfO2 film were 1.2nm. The electrical properties of HfO2 films were improved by optimization of preparation condition. The leakage current density at 1V was below 10-5A/cm2. The dielectric constant was about 20. The loss tangent was below 0.1.

Abstract: The HfO2 films prepared from alkoxy-derived precursor solution chemically modified with diethanolamine. The effects of UV irradiation on the HfO2 films were investigated. The UV irradiation using low pressure mercury lamp (LPML) was effective for the organics decomposition in the film and densification. The uniform and smooth HfO2 films were obtained. The refractive index of HfO2 films was enhanced.

Abstract: HfO2 precursor solutions were prepared by modification of alkoxide for patterning of HfO2 films. The HfO2 dots were patterned on Si substrate by inkjet printing method. The electrical properties of HfO2 films prepared by inkjet printing method were almost same as the properties of the HfO2 films prepared by spin-coating method. Additionally, the HfO2 nanostructures were successfully patterned by nanoimprint method using the chemically-modified alkoxy-derived precursor solution.

Abstract: Ferroelectric Pb(Zr0.6Ti0.4)O3 (PZT(60/40)) powder was prepared by a sol-gel method and PZT thick films were fabricated by the screen-printing method on the alumina substrates. The Pt bottom electrodes were screen-printed on the alumina substrate. The PZT(60/40) thick films were annealed at 1050°C for 10min in PbO atmosphere. Pb(Zr0.4Ti0.6)O3 (PZT(40/60)) precursor solution, which prepared by sol-gel method, was spin-coated on the PZT thick films to obtain a densification. These PZT multilayered thick films were annealed at 650°C for 2 h in PbO atmosphere. The upper electrodes were fabricated by screen printing the Ag paste and then firing at 590°C for 10min. Its structural and electrical properties of the PZT thick films with the treatment of PZT(40/60) precursor solution coating were investigated. The coating and drying procedure was repeated 4 times. And then the PZT(40/60) precursor solution was spin-coated on the multilayered thick films. A concentration of a coating solution was 1.5 mol/L and the number of coating was repeated from 0~15. The porosity of the thick films was decreased with increasing the number of coatings. All PZT multilayered thick films showed the XRD patterns of typical peroveskite polycrystalline structure. The relative dielectric constant of the PZT-15 (15: number of solution coatings) thick film were 370. And the PZT-15 thick film shows the remanent polarization of 23.5 μC/cm2 and coercive field of 18.0 kV/cm, respectively.

Abstract: The uniform Sr0.5Ba0.5Bi4Ti4O15 thin films were prepared using a modified Sol-Gel technique and the influence of precursor on the microstructure and characterization of thin films were studied. The stability and uniformity of precursor solution is key issue for the quality of thin films. Ethanolamine is an effective complexation reagent of Bi3+, which could moderate the acidity of precursor. When pH value and concentration of precursor solution was about 3.5 and 0.35M respectively, the smooth and uniform Sr0.5Ba0.5Bi4Ti4O15 thin films could be obtained. The Bi-layered perovskite structure of Sr0.5Ba0.5Bi4Ti4O15 formed at 750°C. The morphology of the grains in Sr0.5Ba0.5Bi4Ti4O15 thin films was elliptoid and the grain size was about 90 ~ 100 nm.

Abstract: The UV-Vis absorption spectrum of ZrO2 precursor solution containing 4-(phenylazo)benzoic acid (C6H5N=NC6H4COOH) reversibly changed accompanied with reversible change of the spectrum of 4-(phenylazo)benzoic acid by light irradiation. However, the spectrum of ZrO2 precursor solution containing azobenzene (C6H5N=NC6H5) did not change accompanied with reversible change of azobenzene by light irradiation. Furthermore, the back reaction of ZrO2 precursor solution containing 4-(phenylazo)benzoic acid by visible light irradiation was suppressed even if the back reaction of 4-(phenylazo)benzoic acid has occurred by visible light irradiation, when the hydrolysis of ZrO2 precursor was suitably controlled.