scholarly journals Influence of the growth parameters on TiO2 thin films deposited using the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (308) ◽  
pp. 192-198 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  

In this work we report the synthesis of TiO2 thin films by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during the growth in the obtained structural characteristics was studied. Different temperatures of the organometallic bath, deposition time, temperature and type of the substrate were combined. Using Scanning Electron Microscopy associated to Electron Dispersive X-Ray Spectroscopy, Atomic Force Microscopy and X-ray Diffraction, the strong influence of these parameters in the thin films final microstructure was verified.

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.


2012 ◽  
Vol 490-495 ◽  
pp. 3306-3310
Author(s):  
Fei Gao ◽  
Xiao Yan Liu ◽  
Li Yun Zheng ◽  
Mei Xia Li ◽  
Rui Jiao Jiang

TiO2 and Ni-doped TiO2 thin films were prepared by DC magnetron sputtering. The effects of Ni-doping on the microstructure and properties were studied by atomic force microscopy (AFM), X-ray diffraction (XRD), UV-Vis spectra and photocatalysis tesing, respectively. The results show that TiO2 thin films were successfully prepared with smooth surface. When doped with Ni, the surface of TiO2 thin film was improved and the growth of anatase phase was also promoted. With increasing the sputtering power of Ni, the absorption edge wavelegth red shifted and the photocatalysis property of TiO2 thin films was increased and then decreased


2015 ◽  
Vol 22 (01) ◽  
pp. 1550011 ◽  
Author(s):  
PARTHASARATHI BERA ◽  
M. DINESH KUMAR ◽  
CHINNASAMY ANANDAN ◽  
C. SHIVAKUMARA

Ni – W alloy coatings are electrodeposited with direct and pulse current using gluconate bath at pH5. Effects of direct current (DC) and pulse current (PC) on structural characteristics of the coatings have been investigated by energy dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). EDXS shows that W contents are 13.3 and 12.6 at.% in DC and PC (10:40) Ni – W coatings, respectively. FESEM analysis exhibits the homogeneous coarse nodular morphology in DC plated deposits. DSC studies reveal that Ni – W coatings are thermally stable up to 400°C. XPS studies demonstrate that DC plated coating has significant amount of Ni and W in elemental form along with their respective oxidized species. In contrast, mainly oxidized metals are present in the as-deposited coatings prepared with PC plating. The microhardness of pulse current (100:400) deposited Ni – W coating is about 750 HK that is much higher than DC plated coating (635 HK). Heat treatment of the deposits carried out at different temperatures show a significant increase in microhardness which can be comparable with hard chromium coatings.


2005 ◽  
Vol 20 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Zhaoming Zhang

Epitaxial anatase TiO2 thin films were successfully grown on lattice-matched SrTiO3 (001) substrates by a novel hydrothermal method at very low temperatures (120–200 °C). This method is extremely simple and inexpensive in that the SrTiO3 substrate itself provides the source material for the TiO2 film. X-ray diffraction confirmed the high crystallinity and phase purity of the anatase films. The epitaxial relationship between the film and the substrate was determined as (001)[100]anatase // (001)[100]SrTiO3. Atomic force microscopy revealed the average size of the anatase crystallites as approximately 50 to 200 nm.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


1999 ◽  
Vol 597 ◽  
Author(s):  
M. Siegert ◽  
Judit G. Lisoni ◽  
C. H. Lei ◽  
A. Eckau ◽  
W. Zander ◽  
...  

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.


1999 ◽  
Vol 38 (4) ◽  
pp. 684 ◽  
Author(s):  
Victor E. Asadchikov ◽  
Angela Duparré ◽  
Stefan Jakobs ◽  
Albert Yu. Karabekov ◽  
Igor V. Kozhevnikov ◽  
...  

2003 ◽  
Vol 780 ◽  
Author(s):  
C.Z. Dinu ◽  
R. Tanasa ◽  
V.C. Dinca ◽  
A. Barbalat ◽  
C. Grigoriu ◽  
...  

AbstractPulsed Laser Deposition method (PLD) was used to grow nitinol (NiTi) thin films with goal of investigating their biocompatibility. High purity Ni and Ti targets were alternatively ablated in vacuum with a laser beam (λ=355 nm, 10 Hz) and the material was collected on room temperature Ti substrates. X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and atomic force microscopy analyses have been performed to investigate the chemical composition, crystalline structure and surface morphology of the NiTi films. The nitinol layers biocompatibility has been tested using as a metric the extent to whichthe cells adhereduring the culture period on the surface of NiTi layers deposited on Ti substrates. Vero and fibroblast cell lines dispersed into MEM (Eagle) solution containing 8% fetal bovine serum, at 37° C, were used for tests. Preliminary studies indicate that the interaction at the interface is specifically controlled by the surface morphology, (especially by surface roughness), and by the chemical state of the surface. Cell behavior after contact with NiTi/Ti structure for different intervals (18, 22 and 25 days for the Vero cells, and after 10 and 25 days for fibroblasts) supports the conclusion that NiTi is a very good candidate as a biocompatible material.


2012 ◽  
Vol 151 ◽  
pp. 314-318
Author(s):  
Ching Fang Tseng ◽  
Cheng Hsing Hsu ◽  
Chun Hung Lai

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.


2001 ◽  
Vol 696 ◽  
Author(s):  
Ravi Bathe ◽  
R.D. Vispute ◽  
Daniel Habersat ◽  
R. P. Sharma ◽  
T. Venkatesan ◽  
...  

AbstractWe have investigated the epitaxy, surfaces, interfaces, and defects in AlN thin films grown on SiC by pulsed laser deposition. The stress origin, evolution, and relaxation in these films is reported. The crystalline structure and surface morphology of the epitaxially grown AlN thin films on SiC (0001) substrates have been studied using x-ray diffraction (θ–2θ, ω, and Ψ scans) and atomic force microscopy, respectively. The defect analysis has been carried out by using Rutherford backscattering spectrometry and ion channeling technique. The films were grown at various substrate temperatures ranging from room temperature to 1100 °C. X-ray diffraction measurements show highly oriented AlN films when grown at temperatures of 750- 800 °C, and single crystals above 800 °C. The films grown in the temperature range of 950 °C to 1000 °C have been found to be highly strained, whereas the films grown above 1000 °C were found to be cracked along the crystallographic axes. The results of stress as a function of growth temperature, thermal mismatch, growth mode, and buffer layer thickness will be presented, and the implications of these results for wide band gap power electronics will be discussed.


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