Influence of viscosity and ionic concentration on morphology of PLZT thin films

PLZT thin films were prepared by a dip-coating process using Pechini's method. The PLZT solution was obtained from the mixture of the cation solutions. The viscosity of the solution was adjusted in the range of 20-40 cP, while the ionic concentration was adjusted in the range of 0.1 and 0.2 M. PLZT solutions were deposited on Si (1 0 0) substrate with withdrawal speed at 5 mm/min. The coated substrates were thermally treated with heating rate of 1 degreesC/min up to 300 and 5 degreesC/ min up to 650 degreesC in order to obtain homogeneous and crack free films. The influence of viscosity and ionic concentration on crystallization and morphology of PLZT (9/65/35) thin film will be discussed. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Influence of oxygen atmosphere on crystallization and properties of LiNbO3 thin films

Thin films of lithium niobate were deposited on the Pt/Ti/SiO2 (111) substrates by spin coating from the polymeric precursor method (Pechini process). Annealing in static air and oxygen atmosphere was performed at 500 degreesC for 3 h. The films obtained were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The dielectric constant and dissipation factor were measured in frequency region from 10 Hz to 10 MHz. Electrical characterization of the films pointed to ferroelectricity via hysteresis loop. The influence of oxygen atmosphere on crystallization, morphology and properties of LiNbO3 thin films is discussed. (C) 2003 Elsevier Ltd. All rights reserved.

Characterization of lanthanum-doped bismuth titanate thin films prepared by polymeric precursor method

Lanthanum-modified bismuth titanate, Bi4-xLaxTi3O12 (BLT), with x ranging from 0 to 0.75 was grown on Pt/Ti/SiO2/Si substrates using a polymeric precursor solution and spin-coating method. The dielectric constant of highly doped bismuth titanate was equal to 148 while dielectric losses remained low (tan delta = 0.0018), and the films showed well-saturated polarization-electric field curves (2P(r) = 40.6 muC/cm(2) and V-c = 0.99 V). The leakage current densities improve for the lanthanum-doped system. For five-layered BLT films with x = 0.75, a charge storage density of 35 fC/mum(2) and a thickness of 320 nm were found. (C) 2004 Elsevier B.V. All rights reserved.

Photoluminescent CaCu3Ti4O12-Based Thin Films Synthesized by a Sol-Gel Method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of annealing atmosphere on phase formation and electrical characteristics of bismuth ferrite thin films

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dependence of annealing time on structural and morphological properties of Ca(Zr0.05Ti0.95)O-3 thin films

Ca(Zr0.05Ti0.95)O-3 (CZT) thin films were prepared by the polymeric precursor method by spin-coating process. The films were deposited on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates and annealed at 650 degrees C for 2,4, and 6 It in oxygen atmosphere. Structure and morphology of the CZT thin films were characterized by the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and field-emission scanning electron microscopy (FEG-SEM). XRD revealed that the film is free of secondary phases and crystallizes in the orthorhombic structure. The annealing time influences the grain size, lattices parameter and in the film thickness. (c) 2006 Elsevier B.V. All rights reserved.

Improvement of fatigue resistance on La modified BiFeO(3) thin films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Size effects of polycrystalline lanthanum modified Bi4Ti3O12 thin films

The film thickness dependence on the ferroelectric properties of lanthanum modified bismuth titanate Bi3.25La0.75Ti3O12 was investigated. Films with thicknesses ranging from 230 to 404 nut were grown on platinum-coated silicon substrates by the polymeric precursor method. The internal strain is strongly influenced by the film thickness. The morphology of the film changes as the number of layers increases indicating a thickness dependent grain size. The leakage current, remanent polarization and drive voltage were also affected by the film thickness. (c) 2007 Elsevier Ltd. All rights reserved.

SrBi2(Ta0.5Nb0.5)(2)O-9 : W thin films obtained by chemical solution deposition: Morphological and ferroelectric characteristics

The effect of tungsten (W6+) ion substituting on dielectric and ferroelectric behavior in SrBi2(Ta0.5Nb0.5)(2)O-9 (SBTN) thin films prepared by polymeric precursor method was investigated at room temperature. The addition of W6+ ion in the SBTN lattice was evaluated by X-ray diffraction (XRD), microstructural and dielectrical properties. An increase in the grain size is evident when tungsten is introduced in the SBTN lattice. Substitution of tungsten until 10% on B site leads to introduce space charge polarization into the system, resulting in an appreciable decrease in both dielectric constant and tangent loss. The morphology of the thin films investigated by atomic force microscopy leads to an increase in the grain size after tungsten addition. Fatigue resistance was noted with increase in tungsten addition. (C) 2007 Elsevier B.V. All rights reserved.