scholarly journals Photo-Induced Super-hydrophilic Thin Films on Quartz Glass by UV Irradiation of Precursor Films Involving a Ti(IV) Complex at Room Temperature

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 348 ◽  
Author(s):  
Hsiang-Jung Wu ◽  
Kota Tanabe ◽  
Hiroki Nagai ◽  
Mitsunobu Sato
Keyword(s):  
Thin Films ◽  
Uv Irradiation ◽  
Quartz Glass ◽  
Room Temperature ◽  
Contact Angles ◽  
Chemical Components ◽  
Precursor Film ◽  
Dark Condition ◽  
Xps Spectra ◽  
Molecular Precursor

Photo-induced super-hydrophilic thin films were fabricated on a quartz glass substrate by ultraviolet (UV) irradiation of a molecular precursor film at room temperature. A molecular precursor film exhibiting high solubility to both ethanol and water was obtained by spin-coating a solution involving a Ti(IV) complex; this complex was prepared by the reaction of Ti(IV) alkoxide with butylammonium hydrogen oxalate and hydrogen peroxide in ethanol. Transparent and well-adhered amorphous thin films of 160–170 nm thickness were obtained by weak UV irradiation (4 mW·cm−2 at 254 nm) of the precursor films for over 4 h at room temperature. The resultant thin films exhibiting low refractive indices of 1.78–1.79 were mechanically robust and water-insoluble. The chemical components of the thin films were examined by means of Fourier transform-infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) spectra, focusing on the presence of the original ligands. The super-hydrophilic properties (evaluated based on the water contact angles on the surfaces) of the thin films after being kept in a dark condition overnight emerged when the aforementioned UV-light irradiation was performed for 10 min. It was additionally clarified that the super-hydrophilicity can be photo-induced repeatedly by UV irradiation for 10 min (indicated by a contact angle smaller than 4°) even after the hydrophilic level of the thin films had once been lowered by being in a dark condition for 4 h.

Selective formation of cubic or tetragonal zirconia thin films of transparent, with no use of metal ion stabilizer by heating molecular precursor films under mild conditions

2021 ◽  
Vol 14 (02) ◽  
pp. 2151012
Author(s):  
Natangue Heita Shafudah ◽  
Hiroki Nagai ◽  
Mitsunobu Sato
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Quartz Glass ◽  
Glass Substrate ◽  
Metal Ion ◽  
Tetragonal Zirconia ◽  
Precursor Film ◽  
Quartz Glass Substrate ◽  
Molecular Precursor ◽  
Zirconia Thin Film

Cubic or tetragonal zirconia thin films of transparent and 100 nm thickness were selectively formed on a quartz glass substrate by heat-treating the molecular precursor films involving Zr(IV) complexes of nitrilotriacetic acid, at 500[Formula: see text]C in air for 1 h. A precursor solution was prepared by a reaction of the ligand and zirconium tetrabutoxide in alcohol under the presence of butylamine. By the addition of H2O2 or H2O into the solution, the spin-coated precursor films were converted to cubic zirconia thin films by the abovementioned procedure. Further, the identical phase was produced also in the case of the electro-sprayed precursor film which was formed by an addition of H2O2 into the solution. On the other hand, the tetragonal zirconia thin film was obtained from a precursor film formed by using a solution dissolving the original Zr(IV) complex of the ligand, without H2O2 nor H2O. The crystal structure of all thin films was determined by using both the X-ray diffraction (XRD) patterns and Raman spectra. Thus, the zirconia thin films of both crystals could be facilely and selectively obtained with no use of hetero-metal ion stabilizers. The XPS spectra of the thin films show that the O/Zr ratio of the cubic phase is 1.37 and slightly larger than tetragonal one (1.29), and also demonstrate that the nitrogen atoms, which may contribute to stabilize these metastable phases at room temperature, of about 5−7 atomic% was remained in the resultant thin films. The adhesion strengths of cubic zirconia thin film onto the quartz glass substrate was 68 MPa and larger than that of tetragonal one, when the precursor films were formed via a spin coating process. The optical and surface properties of the thin films were also examined in relation to the crystal systems.

scholarly journals Deep-Ultraviolet Transparent Conductive MWCNT/SiO2 Composite Thin Film Fabricated by UV Irradiation at Ambient Temperature onto Spin-Coated Molecular Precursor Film

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1348
Author(s):  
Hiroki Nagai ◽  
Naoki Ogawa ◽  
Mitsunobu Sato
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Heat Treatment ◽  
Uv Irradiation ◽  
Composite Thin Film ◽  
Precursor Film ◽  
Mixed Solution ◽  
Pencil Hardness ◽  
Strong Base ◽  
Deep Ultraviolet

Deep-ultraviolet (DUV) light-transparent conductive composite thin films, consisting of dispersed multiwalled carbon nanotubes (MWCNTs) and SiO2 matrix composites, were fabricated on a quartz glass substrate. Transparent and well-adhered amorphous thin films, with a thickness of 220 nm, were obtained by weak ultraviolet (UV) irradiation (4 mW cm−2 at 254 nm) for more than 6 h at 20−40 °C onto the precursor films, which were obtained by spin coating with a mixed solution of MWCNT in water and Si(IV) complex in ethanol. The electrical resistivity of MWCNT/SiO2 composite thin film is 0.7 Ω·cm, and transmittance in the wavelength region from DUV to visible light is higher than 80%. The MWCNT/SiO2 composite thin film showed scratch resistance at pencil hardness of 8H. Importantly, the resistivity of the MWCNT/SiO2 composite thin film was maintained at the original level even after heat treatment at 500 °C for 1 h. It was observed that the heat treatment of the composite thin film improved durability against both aqueous solutions involving a strong acid (HCl) and a strong base (NaOH).

Investigation of ZnO Based Thin Films as Resistance Materials with Small Temperature Coefficients

2006 ◽  
Vol 45 ◽  
pp. 2376-2381
Author(s):  
Yuichi Sato ◽  
Makoto Goto ◽  
Junji Ikeda ◽  
Yusuke Minakawa ◽  
Susumu Sato
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Quartz Glass ◽  
Room Temperature ◽  
Small Temperature ◽  
Glass Substrates ◽  
Temperature Coefficients ◽  
Temperature Dependences

Possibilities of ZnO based thin films for applications as resistance materials with small temperature coefficients are investigated. The ZnO based thin films containing Cu, Mg, Al and In are deposited on sapphire c-face single crystal substrates or quartz glass substrates. Resistivities at room temperature and their temperature dependences of the obtained thin films are measured and discussed.

scholarly journals Enhancing electrical properties of carbon nanotubes thin films by silicon incorporation

2021 ◽  
Vol 1206 (1) ◽  
pp. 012028
Author(s):  
Sk Faruque Ahmed ◽  
Mohibul Khan ◽  
Nillohit Mukherjee
Keyword(s):  
Thin Films ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Xps Spectra ◽  
X Ray ◽  
Vapor Deposition Technique

Abstract Silicon incorporated carbon nanotube (Si-CNTs) thin films was prepared by radio frequency plasma enhanced chemical vapor deposition technique. Tetraethyl orthosilicate solution was used for incorporation of silicon in CNTs thin films. Energy dispersive X-ray analysis shows that the silicon atomic percentage was varied from 0 % to 6.1 %. The chemical binding energies of carbon and silicon were analyzed from X-ray photoelectron spectroscopy data. The various peaks at ~531 eV, ~ 285 eV, ~155 eV and ~104 eV was observed in the XPS spectra due to the oxygen, carbon and silicon respectively. Surface morphologies of Si-CNTs thin films have been analyzed by field emission scanning electron microscopy, which revels that the length of the silicon incorporated carbon nanotubes ~500 nm and corresponding diameter ~80 nm. The room temperature electrical conductivity was increased whereas the activation energy was decreased with the increase of atomic percentage of silicon in Si-CNTs thin films. The room temperature electrical conductivity was increased from 4.3 × 103 to 7.1 × 104 S cm−1 as the silicon atomic percentage in Si-CNTs thin films increases from 0 to 6.1 % respectively.

Self-Cleaning TiO2 Nanofilms on FTO Glass: Influence of Electrophoretic Deposition and UV Irradiation Conditions

2015 ◽  
Vol 30 ◽  
pp. 39-49 ◽  
Author(s):  
Nazila Horandghadim ◽  
Mohammad Ghorbani ◽  
Abolghasem Dolati
Keyword(s):  
Uv Irradiation ◽  
Applied Voltage ◽  
Water Droplet ◽  
Room Temperature ◽  
Average Particle Size ◽  
Contact Angles ◽  
Average Particle ◽  
Uv Illumination ◽  
Self Cleaning ◽  
Fto Glass

In this research, anatase TiO2nanoparticles were electrophoretically deposited on the FTO glass. This investigation was focused on the self-cleaning property of TiO2coatings and the effects of different parameters on this characteristic such as: applied voltages during electrophoretic depositions and durations of UV irradiation. Electrophoretic depositions of suspensions were performed in different voltages of 10, 30 and 60 V (for 10 s) at room temperature. TiO2coatings were sintered in 450°C for 1 hr. The phase transformation of TiO2films was considered using XRD. Morphology, average particle size and the thickness of TiO2films was analyzed using FESEM microscope. The photocatalytic activity of TiO2films was evaluated by the degradation of aqueous methyl orange (MO) under UV irradiation. The ultraviolet-visible spectrophotometer was used to record the changes of the adsorbancy of the MO solution. Hydrophilicity of TiO2films was determined by measuring contact angle of water droplet with the surface of TiO2films. Results represented that decomposition rate of MO solution by TiO2films enhances from 6.5% to 31% by increasing applied voltage of deposition from 10 to 60V and from 5% to 40% by increasing UV illumination duration from 1 to 5 hours. It was also observed that the contact angles of water droplet with the surface of TiO2films decrease from 34oto 6.6oby increasing applied voltage from 10 to 60V.

scholarly journals Mesoscale organization of titania thin films enables oxygen sensing at room temperature

2017 ◽  
Vol 5 (45) ◽  
pp. 11815-11823 ◽  
Author(s):  
Pietro Rassu ◽  
Luca Malfatti ◽  
Davide Carboni ◽  
Maria F. Casula ◽  
Sebastiano Garroni ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Area ◽  
Uv Irradiation ◽  
Room Temperature ◽  
Oxygen Sensor ◽  
Oxygen Sensing ◽  
Mesoporous Titania ◽  
Mesoporous Film ◽  
Titania Films

We developed an oxygen sensor based on mesoporous titania films working at RT under UV irradiation. Due to larger surface area and number of defects, the mesoporous film exhibits a response higher than dense titania.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Interactions Between Al and Cr Thin Films

1976 ◽  
Vol 34 ◽  
pp. 638-639
Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Vacuum System ◽  
Processing Temperature ◽  
Diffusion Couples ◽  
Electronic Circuits ◽  
Intermetallic Formation ◽  
Si Substrates ◽  
Aluminum Silicon

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.

Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

1990 ◽  
Vol 48 (4) ◽  
pp. 6-7
Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Multilayer Structures ◽  
Rf Power ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Single Target ◽  
Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

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