• Transactions of the Korean hydrogen and new energy society
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• v.10 no.3
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• pp.171-175
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• 1999

Pd films($180{\sim}670{\AA}$ thick) were made by thermal evaporation. Electrical resistance of the films was measured during hydrogen absorption-desorption process at room temperature. Resistance changes as a function of hydrogen pressure in thin films of the PdH system show a strong dependence on film thickness. $({\Delta}R_{\infty}/R_0)_{{\beta}min}$ for a $\670{\AA}$ film is 0.61. For a $\180{\AA}$ film, this is 0.34. Resistance change also depends on sample preparation condition.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.25-30
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• 1995

The frequenc dependence of magnetic permeability($\mu$r) and dielectric constant($\varepsilon$r) in MHz-GHz frequency range and their relationships with microwave absorbing properties were investigated in sintered and composite Ni-Zn ferrites, respectively. It was confirmed that zero reflection condition was required the real parts of permeability and permittivity in sintered specimen, and the complex permeability, permittivity and dielectric loss tangent in composite specimen. The real part of permittivity varied with the replacement of nickel by manganese in sintered Ni-Zn ferrite. Therefore, we could control the matching frequency and matching thickness.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1217-1222
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• 1996

Undoped barium titanate ceramic samples with high density were produced by using both high purity hydro-thermally synthesized and oxalate-derived powders. Sintering temperature was varied in the temperature range 128$0^{\circ}C$-140$0^{\circ}C$ to control the average grain sizes of the samples. Electrical breakdown test was performed at two different temperature with 3$0^{\circ}C$(below Tc) and 15$0^{\circ}C$ (above Tc) for samples immersed in silicon oil bath using 60kV dc power supply. From the experimental results at below and above Curie temperature the grain size and thickness dependence of electrical breakdown strength for BaTiO3 ceramics was presented and breakdown behavior was also studied.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1648-1650
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• 1996

In present paper, Cu films $4{\mu}m$, thick were fabricated by dual deposition methods using RF magnetron sputtering on Si wafer. The dependence of the electrical resistivity, adherence, and reflection in Cu films [$Cu_{4-x}$(low resistivity) / $Cu_x$(high adherence) / Si- wafer] on the x thickness have been investigated. Cu films of $4{\mu}m$ thickness formed with dual deposition methods had the low electrical resistivity of about $2.6{\mu}{\Omega}{\cdot}cm$ and high adherence of about 700g/cm. In conclusion, it is possible for these films to be used for micro-devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2416-2419
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• 2009

We performed frequency response measurements of four tuning fork crystal oscillators with different sizes and analyzed their measured electrical equivalent circuit parameters of R, L, $C_S$, and $C_P$ as functions of the linear dimensions, length, width, and thickness. We observed that R and L showed an decreasing behavior with increasing length while $C_S$, and $C_P$ showed an increasing behavior. Similar dependences of the electrical parameters on thickness were also observed. On the contrary, any noticeable dependence of these parameters on width has not been found.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.53-57
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• 2002

Reduction of insulation thickness would be beneficial not only for increasing the cable length but would also improve its thermal performance. An interfacial diffusion method was devised to reduce insulation thickness by improving the interfacial properties of XLPE cable insulation. In this paper, to evaluate superficially the interface properties between XLPE insulation and semiconducting layer, the dielectric and insulation properties of tan${\delta}$ and volume resistance were measured with temperature dependence. Above the results, dielectirc and insulation properties with semiconductor/XLPE were more anormal than its bulk caused by the interfacial properties.

• Journal of the Korean institute of surface engineering
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• v.35 no.5
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• pp.289-294
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• 2002

ZnTe films have been grown on (100) GaAs substrate with two representative problems. The one is lattice mismatch, the other is thermal expansion coefficients mismatch of ZnTe /GaAs. It claims here, the relationship of film thickness and defects distribution with (100) ZnTe/GaAs using hot wall epitaxy (HWE) growth was investigated by transmission electron microscopy (TEM). It analyzed on the two-sort side using TEM with cross-sectional transmission electron microscopy (XTEM) and high-resolution electron microscopy (HREM). Investigation into the nature and behavior of dislocations with dependence-thickness in (100) ZnTe/ (100) GaAs hetero-structures grown by transmission electron microscopy (TEM). This defects range from interface to 0.7 $\mu\textrm{m}$ was high density, due to the large lattice mismatch and thermal expansion coefficients. The defects of low density was range 0.7$\mu\textrm{m}$~1.8$\mu\textrm{m}$. In the thicker range than 1.8$\mu\textrm{m}$ was measured hardly defects.

• Current Optics and Photonics
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• v.2 no.4
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• pp.378-382
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• 2018

In most previous investigations of plasmonic and metamaterial applications, the metallic film has been regarded as a perfect electrical conductor. Here we demonstrate the resonance characteristics of THz metamaterials fabricated from metal film that has a finite dielectric constant, using finite-difference time-domain simulations. We found strong redshift and spectral broadening of the resonance as we decrease the metal's plasma frequency in the Drude free-electron model. The frequency shift can be attributed to the effective thinning of the metal film, originating from the increase in penetration depth as the plasma frequency decreases. On the contrary, only peak broadening occurs with an increase in the scattering rate. The metal-thickness dependence confirms that the redshift and spectral broadening occur when the effective metal thickness drops below the skin-depth limit. The electromagnetic field distribution illustrates the reduced field enhancement and reduced funneling effects near the gap area in the case of low plasma frequency, which is associated with reduced charge density in the metal film.

• Journal of Magnetics
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• v.4 no.1
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• pp.17-21
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• 1999

The GMR ($d_Cu$) oscillatory behaviour as well as the widths of first and the second antiferromagnetically coupled ranges of the Permalloy ($Py=Ni_{83}Fe_{17}$)/Cu multilayers have been found to be strongly affected not only by the presence of the superparamagnetic/paramagnetic entitles located at the Py/Cu interfaces but mainly by the existence of the magnetic bridges between Py layers. The effectiveness of the magnetic bridges has been found to be temperature dependent, leading to the temperature dependence of the remnant to saturation magnetization ratio ($M_R/M_S$). We have found that for Py/Cu multilayers with equal Py and Cu layer thicknesses a high field sensitivity of the GMR effect (0.4%/Oe) and negligible hysteresis can be achieved when the number of Py layers decreases from 100 to 6. Sensitivity can be further improved by increasing the Py layers thickness, but the hysterstic effect becomes more pronounced then.

• Journal of Magnetics
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• v.2 no.4
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• pp.138-142
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• 1997

The magnetic and magneto-optical properties of Ni/Pt multilayers exhibiting square Kerr hysterisis loops at room temperature were studied. Squared polar Kerr hysterisis loops at room temperature in Ni/Pt multilayer thin films were obtained for the samples prepared by sequential dc magnetron sputter deposition of nickel and platinum with tNi=13-21$\AA$ and tPt=3.5-7.5$\AA$. The coercivity of these multilayers was in the range of 400-1100 Oe. The saturation magnetization was found to show an inverse dependence on nickel sublyaer thickness. About a monolayer of Ni at interface was observed to behave less magnetically than the interior Ni atoms. The polar Kerr rotation exhibited an increasing trend with decreasing wavelength in the spectral range of 7000-4000 $\AA$. The maximum of polar Kerr rotation was found to shift to higher wavelengths with increase in nickel sublayer thickness.