• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.127-130
• /
• 2005

The properties of phosphorus doped ZnO multilayer thin films deposited on (001) sapphire substrates by pulsed laser deposition (PLD) were investigated by using annealing treatment at various annealing temperature after deposition. The phosphorus doped ZnO multilayer was composed of phosphorus doped ZnO layer and two pure ZnO layers on sapphire substrate. The structural. electrical and optical properties of the ZnOthin films were measured by X-ray diffraction (XRD). Hall measurements and photoluminescence (PL). As the annealing temperature optimized. the electrical properties of the ZnO multilayer showed a electron concentration of $1.56{\times}10^{16}/cm^3$, a resistivity of 17.97 ${\Omega}cm$. It was observed the electrical property of the film was changed by dopant activation effect as thermal annealing process

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.4
• /
• pp.321-324
• /
• 2013

In this study, The RF magnetron sputter and evaporator was on glass substrates 30 mm ${\times}$ 30 mm OMO multilayer thin film structure is applied to the low-e. Structural and optical properties, a thin film was produced, the variable was placed into a variable deposition time of the oxide layer. According to the XRD measurement results there is no peak that satisfies the Bragg's law ($2dsin{\theta}=n{\lambda}$) which confirmed that it is an amorphous structure. RMS value of the results of the AFM measurement, has a roughness of less than 2 nm. transmittance measurements results, visible light region an average 80%, IR region 40% showed.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.908-909
• /
• 2006

The HTCC based multilayer structure plasma head unit have some difficulties in fabrication due to complicated post-processes, such as heat treatment at reduced atmosphere, re-bonding of each layer, and silver metallization. On the other hand, LTCC based technology provides relatively simple process for multilayer plasma unit except weak mechanical properties. To overcome this problem a combined scheme using both LTCC and HTCC technology has been developed in our group, recently. In this work, we report the structural design, materials selection, joining of LTCC with HTCC substrate, and co-firing process for the fabrication of multilayered atmospheric plasma head unit.

• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.465-469
• /
• 1995

We have investigated the effects of deposition angle on structural and magnetic properties of e-beam evaporated ${(4-{\AA}\;Co/9.2-{\AA}\;Pt)}_{23}$ multilayer thin films prepared on tilted substrates. It was found that the [111] crystallographic orientations of the multilayer thin films were not aligned with colummar growth orientations and they were remained to be normal to the substrate planes even though the deposition angle was severely oblique up to $60^{\circ}$. The analysis of the torque curve reveal that the intrinsic anisotropy energy was monotonically decreased with the deposition angle but the easy axis orientation parallel to the substrate normal was not much influenced by deposition angle.

• Macromolecular Research
• /
• v.16 no.4
• /
• pp.373-378
• /
• 2008

A simple chemical fixation method for the fabrication of layer-by-layer (LbL) polyelectrolyte multilayer (PEM) has been developed to create a large area, highly uniform film for various applications. PEM of weak poly-electrolytes, i.e., polyallylamine hydrogen chloride (PAH) and poly(acrylic acid)(PAA), was assembled on polymer substrates such as poly(methyl methacrylate)(PMMA) and polycarbonate (PC). In the case of a weak polyelectrolyte, the fabricated thin film thickness of the polyelectrolyte multilayers was strongly dependent on the pH of the processing solution, which enabled the film thickness or optical properties to be controlled. On the other hand, the environmental stability for device application was poor. In this study, we utilized the chemical fixation method using glutaraldehyde (GA)-amine reaction in order to stabilize the polyelectrolyte multilayers. By simple treatment of GA on the PEM film, the inherent morphology was fixed and the adhesion and mechanical strength were improved. Both surface tension and FT-IR measurements supported the chemical cross-linking reaction. The surface property of the polyelectrolyte films was altered and converted from hydrophilic to hydrophobic by chemical modification. The possible application to antireflection coating on PMMA and PC was demonstrated.

• Membrane Journal
• /
• v.18 no.2
• /
• pp.185-190
• /
• 2008

In a previous study, we probed the potential of poly(styrene sulfonate) (PSS)/poly(diallyldimethylammonium chloride) (PDADMAC) nanofiltration (NF) membranes for the separation of monovalent anions, with an emphasis on the selective rejection of $F^-$. Remarkably, deposition of $(PSS/PBADMAC)_4PSS$ films on porous alumina supports yielded membranes that exhibited $Cl^-/F^-$ selectivity > 3 with minimal $Cl^-$ rejection, and a solution flux of $3.5m^3/m^2$-day at 4.8 bar. When the number of PSS/PDADMAC bilayers was increased from 4.5 to 5.5, however, $F^-$ rejection decreased from 73% to 50% and $Cl^-/F^-$ selectivity dropped to 1.9. Addition of another bilayer to form $(PSS/PDADMAC)_6$ PSS films resulted in a significant increase in $Cl^-$ rejection to give essentially no $Cl^-/F^-$ selectivity. The decrease of selectivity with deposition of more than 4.5 bilayers was not expected and it was unclear whether this characteristic was substrate independent. In this study, to investigate the effect of substrates on NF performance of multilayer polyelectrolyte membranes, PSS/PDADMAC films were deposited on 50 kDa polyethersulfone (PES) ultrafiltration supports instead of porous alumina supports. The results indicate that, although fluoride rejection and the number of bilayers at which a maximum $F^-$ rejection occurs are different, the trend is similar for both types of substrates. Therefore, we can conclude that the M: characteristics of multilayer polyelectrolyte membranes may be substrate independent.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.1
• /
• pp.17-26
• /
• 2006

We have shown that zeolite microcrystals can be readily organized in the form of uniformly oriented monoand multilayers on various substrates by well-defined chemical linkages based on covalent, ionic, and hydrogen bondings between the microcrystals and the substrates. This finding establishes the fact that micrometer-scale building blocks can be readily organized into organized entities through interconnection of the surface-tethered large number of functional groups. Since zeolite crystals have highly regular and uniform nanochannels and nanopores within them, the resulting mono and multilayers of zeolite microcrystals bear great potential to be utilized in various novel applications.

• Journal of the Korean Magnetics Society
• /
• v.6 no.5
• /
• pp.329-333
• /
• 1996

We have studied the magnetoresistance and the magnetic anisotropy of Cu/(NiFe/Ni/NiFe) metallic multi layers grown on Si(100), Si(111), $4^{\circ}\;tilt-cut\;Si(111)$ or glass substrate. When the multilayer was grown on $4^{\circ}\;tilt-cut\;Si(111)$ with $50\;{\AA}$ of Cu underlayer, an in-plane uniaxial anisotropy was observed. On the other substrates such as Si(100), Si(111) or glass with Cu underlayer, however, no appreciable anisotropy was shown. The multilayer grown with NiFe or Ni underlayer or without underlayer did not show any arnsotropy even on $4^{\circ}\;tilt-cut\;Si(111)$. When $10\;{\AA}$ of NiFe was deposited prior to the Cu underlayer, the anisotropy in Cu/(NiFe/Ni/NiFe) multilayer disappeared.

• Journal of the Optical Society of Korea
• /
• v.17 no.5
• /
• pp.423-427
• /
• 2013

We present the preparation and characteristics of liquid-phase sensors based on nano-porous silicon multilayer structures for determination of organic content in gasoline. The principle of the sensor is a determination of the cavity-resonant wavelength shift caused by refractive index change of the nano-porous silicon multilayer cavity due to the interaction with liquids. We use the transfer matrix method (TMM) for the design and prediction of characteristics of microcavity sensors based on nano-porous silicon multilayer structures. The preparation process of the nano-porous silicon microcavity is based on electrochemical etching of single-crystal silicon substrates, which can exactly control the porosity and thickness of the porous silicon layers. The basic characteristics of sensors obtained by experimental measurements of the different liquids with known refractive indices are in good agreement with simulation calculations. The reversibility of liquid-phase sensors is confirmed by fast complete evaporation of organic solvents using a low vacuum pump. The nano-porous silicon microcavity sensors can be used to determine different kinds of organic fuel mixtures such as bio-fuel (E5), A92 added ethanol and methanol of different concentrations up to 15%.

• Journal of the Korean institute of surface engineering
• /
• v.57 no.1
• /
• pp.14-21
• /
• 2024

For this study, CrAlN multilayer coatings were deposited on SKD61 substrates using a multi-arc ion plating technique. The structural characteristics of the CrAlN multilayer coatings were evaluated using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Additionally, the adhesion of the coatings was assessed through scratch testing, and the mechanical strength was evaluated using nanoindentation and tribometric tests for frictional properties. The results show that the CrAlN multilayer coatings possess a uniform and dense structure with excellent mechanical strength. Hardness measurements indicated that the CrAlN coatings have high hardness values, and both the coating adhesion and wear resistance were found to be improved compared to CrN. The addition of aluminum is anticipated to contribute to enhanced durability and wear resistance.