Substrate Influenced Nucleation and Crystallization of LiNbO3 Thin Films Made by Sol-Gel

1993 ◽  
Vol 310 ◽  
Author(s):  
Vikram Joshi ◽  
Debasis Roy ◽  
Martha L. Mecartney
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Sol Gel ◽  
Dissipation Factor ◽  
Dip Coating ◽  
Polycrystalline Films ◽  
Heteroepitaxial Growth ◽  
Oriented Polycrystalline ◽  
Deposited Films

AbstractLithium niobate films were deposited on amorphous carbon, silicate glass, (0001) sapphire, and (100) silicon by spin or dip coating double metal ethoxide sols. The crystallinity and microstructure of the deposited films were examined by XRD and TEM. Crystallization behavior and resulting microstructure were strongly influenced by the type of substrate. The formation of crystalline LiNbO3 on amorphous carbon was detected at room temperature. Randomly oriented polycrystalline films were obtained on glass at 400°C. Choice of one mole of water per mole of ethoxide generated heteroepitaxial growth of LiNbO3 thin films on (0001) sapphire. Oriented but polycrystalline films were obtained on silicon. The electrical behavior of film on silicon was evaluated in metal-ferroelectric-semiconductor configuration. A dielectric constant of 35 and a dissipation factor of 0.004 was measured at 100 KHz.

STRUCTURAL AND FERROELECTRIC CHARACTERIZATION OF PZT THIN FILMS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4460-4464 ◽  
Author(s):  
YING YANG ◽  
ZHIMING CHEN ◽  
GAOYANG ZHAO ◽  
WEIHUA ZHANG
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Relative Dielectric Constant ◽  
Dissipation Factor ◽  
Dip Coating ◽  
Test System ◽  
Pzt Thin Films ◽  
Different Temperatures ◽  
Lcr Meter

Pb(Zr x Ti 1-x ) O 3 (PZT) films were prepared on the ITO coated glass plates in sol-gel dip-coating process and post-annealing at different temperatures. The structural properties of the films were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It is shown that the PZT ferroelectric thin films with (110) preferential orientation and well-crystallized perovskite structure can be obtained after annealing at 680°C for 30 minutes. The P-E hysteresis loops were measured by the Sawyer-Tower test system with a compensation resistor at room temperature. Values of the remanent polarization (Pr) and the coercive electric field (Ec) are 19.36• C/cm 2 and 95 kV/cm, respectively, for the prepared PZT thin films. The relative dielectric constant εr and the dissipation factor tg• of the PZT thin films are equal to 639 and 0.23, respectively, which were measured in a LCR meter.

A Modified Chemical Route for Synthesis of Zirconia Thin Films Having Tunable Porosity

2008 ◽  
Vol 1074 ◽  
Author(s):  
Manish Kumar ◽  
G. B. Reddy
Keyword(s):  
Thin Films ◽  
Average Pore Size ◽  
Sol Gel ◽  
Dip Coating ◽  
Porous Films ◽  
Average Pore ◽  
Chemical Route ◽  
Porous Microstructure ◽  
Chemical Synthesis Route ◽  
Deposited Films

ABSTRACTA new chemical synthesis route is reported for deposition of zirconia thin films having adjustable porosity with average pore size in nanometer range. Deposition method is simply a sol-gel dip coating in which HCl is used as catalyst. TEM and FTIR studies of deposited films show porous microstructure, which depends critically on ageing of sol used. The shift in binding energy of Zr 3d5/2 (at 182.4 eV) attributes the formation of zirconia. Optical results show high transmittance (> 80%) in VIS-NIR region and effective refractive indices values (neff) tend to decrease for films prepared with higher aged sol. Porosity enhancement from 15-52% is observed by neff comparing with refractive index of non porous films (nz).

Optical Properties of Nanostructured Sol–Gel Thin Films Doped with Fe2O3 and Their Ferromagnetic Characterization by Mössbauer Spectroscopy

2008 ◽  
Vol 8 (12) ◽  
pp. 6491-6496
Author(s):  
Jorge Garcia-Macedo ◽  
Guadalupe Valverde-Aguilar ◽  
Raúl W. Gómez ◽  
José L. Pérez-Mazariego ◽  
Vivianne Marquina
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Coating Method ◽  
Dip Coating Method

Sol–gel thin films containing Fe2O3 were deposited onto glass substrates by the dip-coating method at room temperature. Fe2O3 enriched with the isotope 57Fe was embedded in two kinds of matrices: zinc oxide (ZnO) and silica (SiO2). X-ray diffraction (XRD) was used for morphology and structure determination of the nanostructures and showed that the ZnO exhibit a wurtzite form when the film is annealed at 450 °C for 20 min. SiO2 thin films at C16H33PEO20:Fe2O3 = 1:2.7 × 10−1 molar concentration exhibit a hexagonal nanophase produced by the diblock copolymer Brij58 (C16H33PEO20). Optical absorption and infrared spectroscopy techniques were used to evaluate the optical quality of the films. In order to determine if the Fe2O3 was incorporated into the matrices, room temperature Mössbauer spectra of both samples were obtained. In both cases the hematite spectrum was obtained, corroborating that the incorporation of the Fe2O3 to the matrices was done without chemical reaction whatsoever.

Room Temperature Photoluminescence of TiO2 Thin Films Doped with Tb

2001 ◽  
Vol 15 (17n19) ◽  
pp. 813-816 ◽  
Author(s):  
A. Conde-Gallardo ◽  
M. García-Rocha ◽  
I. Hernández Calderón ◽  
R. Palomino-Merino
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Sol Gel ◽  
Broad Band ◽  
Dip Coating ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Novel Host ◽  
Coating Method ◽  
Dip Coating Method

Results on the fabrication and characterisation of thin films of the novel host, titania ( TiO 2), for the Tb 3+ activator ion are reported. The titania films were produced by the sol-gel process at room temperature using the dip coating method and deposited on silicon and corning glass substrates. It is shown that a different surface morphology is developed for the TiO 2:Tb films deposited on different substrates. When enough amount of Tb is incorporated and, a He-Cd 325 nm photoexcitation is used as excitation line, the films show green photoluminescence (PL) signal associated with the 5 D 4→7 F j transition of the electronic structure of Tb 3+ plus an broad band due to matrix's defects. The PL emission has better characteristics for the films deposited on silicon wafers.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

The effect of the withdrawal speed on properties of nickel oxide thin films

2019 ◽  
Vol 234 (10) ◽  
pp. 647-655
Author(s):  
Zohra Nazir Kayani ◽  
Atiqa Aslam ◽  
Rabia Ishaque ◽  
Syeda Nosheen Zahra ◽  
Hifza Hanif ◽  
...  
Keyword(s):  
Thin Films ◽  
Nickel Oxide ◽  
Band Gap ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Dip Coating ◽  
Oxide Thin Films ◽  
Withdrawal Speed ◽  
Sem Micrograph ◽  
Nickel Oxide Thin Films

Abstract Nickel oxide thin films have been prepared by sol-gel dip-coating technique on glass substrate. It is shown that nickel oxide thin films have poly crystalline nature. Nickel oxide thin films exhibit high transmission (39–85%) in the wavelength range of 400–900 nm, strong absorption between 300 and 400 nm wavelengths and decrease of band gap values are in the range 3.69–3.27 eV with increase of withdrawal speed. High band gap at low withdrawal speed is because of the small average crystallite size, which decreases with increase in withdrawal speed. The SEM micrograph shows cubic crystallites and surface of thin films become dense, smooth and homogeneous with an increase in withdrawal speed. Assessment of nickel oxide deposition conditions provides gateway for effective and cheap solar cells.

Effect of Precursor Sol Ageing on Sol-Gel Derived Ruthenium Oxide Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Ruthenium Oxide ◽  
Precursor Solution ◽  
Silicon Substrates ◽  
Solution Deposition ◽  
Precursor Material ◽  
Afm Analysis

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.

Sign in / Sign up

Export Citation Format

Share Document