• Journal of the Korean Ceramic Society
• /
• v.29 no.11
• /
• pp.863-869
• /
• 1992

A SOG(spin glass) solution with excellent wetting to Si wafers was prepared by acid-hydrolysis of Si(OEt)4 and Me2Si(OEt)2. The solution was spin coated on Si wafers, and effects of heat treatment of the film were characterized by TG/DTA, FTIR and Ellipsometry. Silica film was obtained by heat treatment at $600^{\circ}C$ within one hour, but heat treatment at 80$0^{\circ}C$ caused interfacial oxidation of the silicon substrate. Unexpectedly silica films with much better adhesion were obtained by curing at $600^{\circ}C$ for over 30 min. than those obtained by thermal oxidation.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2010.06a
• /
• pp.189-190
• /
• 2010

Our results demonstrate the possibility of implementing a chip-cytometer for biological applications using high-sensitive spin-valve devices integrated with a microfluidic channel. Further studies will be extended to the real-time detection of animal cells coated with magnetic beads for the biological applications.

• Journal of Magnetics
• /
• v.16 no.2
• /
• pp.169-172
• /
• 2011

This study reports an alternative method for measuring the magnetoresistance of unpatterned magnetic tunnel junctions similar to the current-in-plane tunneling (CIPT) method. Instead of using microprobes, a series of point contacts with different spacings are coated on the top surface of the junctions and R-H loops at various spacings are then measured by the usual four-point probe method. The values of magnetoresistance and resistance-area products can be obtained by fitting the measured data to the CIPT theoretical model. The test results of two types of junctions were highly similar to those obtained from standard CIPT tools. The proposed method may help to accelerate the process for evaluating the quality of magnetic tunnel junctions when commercial CIPT tools are not accessible.

• Advances in nano research
• /
• v.13 no.5
• /
• pp.417-426
• /
• 2022

Bisphenol A (BPA) is one of the chemicals used in monomer epoxy resins and polycarbonate plastics. The surface-enhanced Raman spectroscopy (SERS) method is precise for identifying biological materials and chemicals at considerably low concentrations. In the present article, the substrates coated with gold nanoparticles have been studied to identify BPA and control the diseases caused by this chemical. Gold nanoparticles were made by a simple chemical method and by applying gold salt and trisodium citrate dihydrate reductant and were coated on glass substrates by a spin-coat approach. Finally, using these SERS substrates as plasmonic sensors and Raman spectroscopy, the Raman signal enhancement of molecular vibrations of BPA was investigated. Then, the molecular vibrations of BPA in some consumer goods were identified by applying SERS substrates as plasmonic sensors and Raman spectroscopy. The fabricated gold nanoparticles are spherical and quasi-spherical nanoparticles that confirm the formation of gold nanoparticles by observing the plasmon resonance peak at 517 nm. Active SERS substrates have been coated with nanoparticles, which improve the Raman signal. The enhancement of the Raman signal is due to the resonance of the surface plasmons of the nanoparticles. Active SERS substrates, gold nanoparticles deposited on a glass substrate, were fabricated for the detection of BPA; a detection limit of 10-9 M and a relative standard deviation (RSD) equal to 4.17% were obtained for ten repeated measurements in the concentration of 10-9 M. Hence, the Raman results indicate that the active SERS substrates, gold nanoparticles for the detection of BPA along with the developed methods, show promising results for SERS-based studies and can lead to the development of microsensors. In Raman spectroscopy, SERS active substrate coated with gold nanoparticles are of interest, which is larger than gold particles due to the resonance of the surface plasmons of gold nanoparticles and the scattering of light from gold particles since the Raman signal amplifies the molecular vibrations of BPA. By decreasing the concentration of BPA deposited on the active SERS substrates, the Raman signal is also weakened due to the reduction of molecular vibrations. By increasing the surface roughness of the active SERS substrates, the Raman signal can be enhanced due to increased light scattering from rough centers, which are the same as the larger particles created throughout the deposition by the spin-coat method, and as a result, they enhance the signal by increasing the scattering of light. Then, the molecular vibrations of BPA were identified in some consumer goods by SERS substrates as plasmonic sensors and Raman spectroscopy.

• 정보저장시스템학회:학술대회논문집
• /
• 2005.10a
• /
• pp.113-118
• /
• 2005

Small form factor optical disks for near-field optics using solid immersion lens were developed. Disk durability properties in terms of head-disk interface (HDI) properties were investigated by drag test, diamond like carbon film and lubricant film were coated on the small form factor disk to enhance HDI. Disks with glass substrates and lubricant films after heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating In which the ski-jump could not be formed by adopting outer ring technique.

• Transactions of the Society of Information Storage Systems
• /
• v.2 no.1
• /
• pp.26-31
• /
• 2006

Small form factor optical disks for near-field optics using solid immersion lens were developed. Diamond like carbon film and lubricant film were coated on the small form factor optical disk to enhance the head-disk interface(HDI) characteristics. The disk durability properties in terms of HDI phenomena were investigated by drag test. Disks with glass substrates and the lubricant films experienced heat treatment showed more durable characteristics. Coverlayers made of UV resin were uniformly coated by spin coating in which the ski-jump could be removed by adopting outer ring technique

• Journal of the Microelectronics and Packaging Society
• /
• v.6 no.1
• /
• pp.39-49
• /
• 1999

Monolayer thick fluorocarbon films were characterized by the contact angle measurements. The contact angles of three different liquids, water, formamide and diiodomethane were measured on spun coated, vapor phased deposited films and Teflon surface. The highest contact angle over $130^{\circ}$was observed on fluorocarbon films deposited on Al substrates while the lowest angles below $70^{\circ}$deposited on oxide. The surface energies were calculated based on Lewis acid /base theory. The surface energies of Teflon and spin coated FC films were calculated to have 18 and 8.4 dynes /cm, respectively. Higher energies of 31 to .35 dynes /cm were calculated on vapor phase deposited films on silicon and oxide. However vapor phase deposited films on aluminum only showed a large Lewis base energy term. It might be explained by the surface roughness and heterogeneity as observed by dynamic contact angles and AFM measurements.

• Journal of the Korean Chemical Society
• /
• v.50 no.3
• /
• pp.243-246
• /
• 2006

The LiCoO2 thin films were prepared on the Pt/Ti/SiO2/Si substrate by spin coating using citrate sol. The citrate sol was spin-coated on substrate and dried at 380oC for 15 min. to evaporate the solvents and remove the organic materials. The as-deposited films were annealed at 750oC for 10 min. in air for crystallization. The X-ray diffraction patterns for the film have been indexed hexagonal system with space group R3m. The active area of LiCoO2 films for electrochemical test was about 11cm2. A Li foil and 1M LiClO4 in propylene carbonate(PC) and ethylene carbonate(EC) (1:1)were used as an anode and an electrolyte, respectively. The galvanostatic charge-discharge test was carried out at constant current density ranging from 5 A/cm2 in the voltage window between 4.2 and 3.0 V. The first discharge capacity of the film is 0.35Ah/cm2-m. The cycling behavior of the LiCoO2 film is also reported.

• Journal of the Korean Ceramic Society
• /
• v.36 no.4
• /
• pp.391-402
• /
• 1999

Characteristics of composite electrolytes which were prepared by coating a thin film of YSZ (yttria sta-bilized zirconia : (ZrO2)0.92 (Y2O3)0.08) on YDC (yttria doped ceria : Ce0.8Y0.2O1.9) with mixed conductivity have been investigated in order to develop the low-temperature solid oxide fuel cell. The thickness (t) of spin-coated YSZ thin films after the heat-treatment at 600$^{\circ}C$ was increased proportionally to the sol con-centrations (C) while the decrease in its thickness with the spin rate ($\omega$) could be expressed in the e-quation of ln t=9.49-0.53 ln $\omega$(0.99mol//s sol conc.) When the sol concentration and the spin rate being less than 0.99 mol/l and higher than 1000 rpm respectively reliable YSZ/YDC composite electrolytes could be obtained by multi-coating although several micro-cracks were observed in singly coated YSZ film surfaces. The dense YSZ film with a 1$\mu\textrm{m}$ thickness was prepared by coating of 0.99 mol/l YSZ sol five-times at 2000 rpm followed by heat-treatment at 1400$^{\circ}C$ for 2h, The adhesion between YSZ film and YDC substrate was found to be very good. The open circuit voltages of H2/O2 single cell with YSZ/YDC composite electrolytes were 0.79∼0.82 V at 800$^{\circ}C$ and 0.75∼0.77V at 900$^{\circ}C$ The open circuit voltage was inversely proportioned to the thickness ratio of YSZ thin film (1$\mu\textrm{m}$) to YDC substrate(0.28-2.22 mm)

• Genomics & Informatics
• /
• v.4 no.3
• /
• pp.133-136
• /
• 2006

The adsorption of proteins on the surface of glass slides is essential for construction of protein chips. Previously, we prepared a nickel-coated plate by the spin-coating method for immobilization of His-tagged proteins. In order to know whether the structural factor is responsible for the immobilization of His-tagged proteins to the nickel-coated glass slide, we executed a series of experiments. First we purified a His-tagged protein after expressing the vector in E. coli BL21 (DE3). Then we obtained the unfolding curve for the His-tagged protein by using guanidine hydrochloride. Fractions unfolded were monitored by internal fluorescence spectroscopy. The ${\Delta}G_{H20}$ for unfolding was $2.27kcal/mol{/pm}0.52$. Then we tested if unfolded His-tagged proteins can be adsorbed to the nickel-coated plate, comparing with $Ni^{2+}-NTA$ (nitrilotriacetic acid) beads. Whereas unfolded His-tagged proteins were adsorbed to $Ni^{2+}-NTA$ beads, they did not bind to the nickel-coated plate. In conclusion, a structural factor is likely to be an important factor for constructing the protein chips, when His-tagged proteins will immobilize to the nickel-coated slides.