Novel route for the epitaxial growth of (SrBa)Nb2O6 thick films by the sol-gel method using a self-template layer

2001 ◽  
Vol 16 (11) ◽  
pp. 3179-3183 ◽  
Author(s):  
A-D. Li ◽  
C. L. Mak ◽  
K. H. Wong ◽  
D. Wu ◽  
Naiben Ming

A novel sol-gel processing method has been developed to fabricate epitaxial (SrBa)Nb2O6 (SBN) thin films on MgO substrates. It involves the introduction of a SBN self-template layer on MgO by pulsed laser deposition (PLD). Effects of the SBN self-template layer on the structural and morphological properties of the sol-gel-derived SBN films were investigated. Compared to the sol-gel-derived SBN films without a self-template layer, our new technique produces SBN films of excellent epitaxy and more dense grains with uniform distribution. This can be explained by the self-template-layer-induced homoepitaxial growth. The innovative processing method with combination of PLD and sol-gel is a promising technique in preparing high-quality, thick epitaxial SBN films for electro-optics device applications.

2008 ◽  
Vol 368-372 ◽  
pp. 308-311
Author(s):  
F.K. Shan ◽  
G.X. Liu ◽  
Byoung Chul Shin ◽  
Won Jae Lee ◽  
W.T. Oh

High-quality In2O3 powder and ZnO powder had been used to make the ceramic target and the atomic ratio of 1 to 1 of indium and zinc had been prepared in this study. The alloyed thin films had been deposited on sapphire (001) substrates at different temperatures (100–600°C) by using pulsed laser deposition (PLD) technique. An x-ray diffractometer and an atomic force microscope were used to investigate the structural and morphological properties of the alloyed thin films. It was observed that the alloyed thin films deposited at the temperatures lower than 300°C were amorphous, and the alloyed thin films deposited at high temperatures were crystallized. A spectrophotometer was used to investigate the transmittances of the alloyed thin films. It was found that the alloyed thin films were of high quality. The band gap energies of the alloys were calculated by linear fitting the sharp absorption edges of the transmittance spectra. The Hall measurements were also carried out to identify the electrical properties of the thin films.


2005 ◽  
Vol 475-479 ◽  
pp. 3807-3810 ◽  
Author(s):  
X.P. Zhang ◽  
Y.S. Xiao ◽  
H. Zhou ◽  
B.T. Xie ◽  
C.X. Yang ◽  
...  

In this paper, we report the growth of NaxCoO2 thin films by pulsed-laser deposition (PLD). It is shown that the concentration of sodium is very sensitive to the substrate temperature and the target-substrate distance due to the evaporation of sodium during the deposition. α'-phase Na0.75CoO2 and γ-phase Na0.71CoO2 thin films can be obtained with different conditions. Correspondingly, the surface morphology of the films changes from flake-like to particle-like. The temperature dependence of resistivity for the films prepared with the optimal condition shows metallic behavior, consistent with the data of NaxCoO2 single crystals. This work demonstrates that PLD is a promising technique to get high quality NaxCoO2 thin films.


2015 ◽  
Vol 3 (9) ◽  
pp. 2115-2122 ◽  
Author(s):  
Wei Sun ◽  
Jing-Feng Li ◽  
Qi Yu ◽  
Li-Qian Cheng

We prepared high-quality Bi1−xSmxFeO3 films on Pt(111)/Ti/SiO2/Si substrates by sol–gel processing and found rhombohedral–orthorhombic phase transition with enhanced piezoelectricity.


2020 ◽  
Author(s):  
Christiane Adler ◽  
Igor Krivtsov ◽  
Dariusz Mitoraj ◽  
Lucía dos Santos-Gómez ◽  
Santiago García-Granda ◽  
...  

In spite of the enormous promise that polymeric carbon nitride (PCN) materials hold for photoelectrochemical (PEC) applications, the fabrication of high-quality PCN photoelectrodes has been a largely elusive goal to date. Here we tackle this challenge by devising, for the first time, a sol–gel approach that enables facile preparation of photoanodes based on poly(heptazine imide) (PHI), a polymer belonging to the PCN family. The sol–gel process capitalizes on the use of a water-soluble PHI precursor composed of nanosized (~10 nm) particles that allows formation of a non-covalent hydrogel. The hydrogel can be deposited on a conductive substrate resulting in formation of mechanically stable porous polymeric thin layers (~400 nm), in contrast to the commonly obtained loosely attached thick particulate coatings. The resulting photoanodes exhibit unprecedented PEC performance in methanol reforming in neutral pH electrolytes with photocurrents of up to 177±27 mA cm<sup>-2</sup> (1 sun illumination) and 320±40 mA cm<sup>-2</sup> (2 sun illumination) at 1.23 V vs. RHE, maintaining such high photocurrents even down to ~0 V vs. RHE. These parameters permit effective operation even without any external electric bias, as demonstrated by bias-free photoreforming of methanol and glycerol, and highly selective (~100%) photooxidation of 4-methoxybenzyl alcohol (4-MBA). The robust binder-free films derived from sol–gel processing of water-soluble PCN thus represent a new paradigm for high-performance ‘soft-matter’ photoelectrocatalytic systems, and pave the way for further applications in which high-quality PCN films are required.


1991 ◽  
Vol 243 ◽  
Author(s):  
K. Nashimoto ◽  
D. K. Fork ◽  
F. A. Ponce ◽  
T. H. Geballe

AbstractEpitaxial growth of ferroelectric thin films on GaAs (100) by pulsed laser deposition was examined for integrated electro-optic device applications. To promote epitaxy of ferroelectrics and prevent interdiffusion, we have deposited several types of buffer layers. CeO2 reacted strongly with GaAs. Although Y203 9% stabilized-ZrO2 films showed epitaxial growth, YSZ reacted with GaAs at 780°C. MgO grew epitaxially and was stable even at 780°C. HRTEM observation showed a sharp interface between MgO and GaAs. BaTiO3 and SrTiO3 deposited on MgO/GaAs structures showed epitaxial growth. In-plane orientation was BaTiO3 [100 // MgO [100] // GaAs [100]. Epitaxial BaTiO3 films were c-axis oriented tetragonal phase and showed ferroelectric hysteresis.


Author(s):  
Adele Carradò ◽  
Agnès Fabre ◽  
Laurent Barrallier ◽  
Nathalie Viart ◽  
I.N. Mihailescu ◽  
...  

2005 ◽  
Vol 30 (1) ◽  
pp. 51-58 ◽  
Author(s):  
C. U. Ferreira ◽  
J. E. Gonçalves ◽  
Y. V. Kholin ◽  
Y. Gushikem

The porous mixed oxide SiO2/TiO2/Sb2O5 obtained by the sol-gel processing method presented a good ion exchange property and a high exchange capacity towards the Li+, Na+ and K+ ions. In the H+/M+ ion exchange process, the H+ / Na+ could be described as presenting an ideal character. The ion exchange equilibria of Li+ and K+ were quantitatively described with the help of the model of fixed tetradentate centers. The results of simulation evidence that for the H+ / Li+ exchange the usual situation takes place: the affinity of the material to the Li+ ions is decreased with increasing the degree of ion exchange. On the contrary, for K+ the effects of positive cooperativity, that facilitate the H+ / K+ exchange, were revealed.


1994 ◽  
Vol 141 (1-2) ◽  
pp. 141-149 ◽  
Author(s):  
J.P. Contour ◽  
D. Ravelosona ◽  
C. Sant ◽  
C. Frétigny ◽  
C. Dolin ◽  
...  

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