• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.270.2-270.2
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• 2008

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.164-164
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• 2000

Since Au-Pt alloys have various atomic structures depending upon composition and annealing temperature, it is very interesting to investigate the electronic structures of alloys. We studied the changes of the electronic structure I the Au-Pt alloys by x-ray absorption near edge spectroscopy (XANES). Two kinds of Au-Pt alloy samples were prepared by arc melting methods and ion-beam-mixing technique. The Pt L2, 3-edge and Au L2, 3-edge X-ray absorption spectra (XPS) were measured with the electron yield mode detector at the 3C1 beam line of the Pohang Light Source (PLS). It was found that there was a substantial decrease in the area of the Pt L2, 3 white lines compared with that of pure Pt. The observed decrease in white line area was attributed to an increase in the number of pure Pt. The observed decrease in white line area was attributed to an increase in the number of 5d-electrons at the Pt site upon alloy formation. However, the Au L2, 3 edge spectra for Au-Pt alloys are all similar to that of pure Au. This implies that the 5d hole count of Au is not changed by alloy formation with Pt.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.135-136
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• 1998

By the ion bombardment the original discrete layered structure is damaged and a uniformly mixed layer is formed by the intermixing of the films. Immediately after this dynamic cascade mixing a structure of this mixed layer is likely to be a mixture of randomly distributed atoms. Subsequently the mixed layered structure becomes a non-equilibrium structure such as the metastable pphase because the kinetic energies of the incident ions rappidly dissippate and host atoms within the collision cascade region are quenched from a highly energetic state. The formation of the metastable transition metal alloys using ion-beam-mixing has been extensively studied for many years because of their sppecific ppropperties that differ from those of bulk materials. in ion-beam-mixing the alloy or comppound is formed due to the atomic interaction between different sppecies during ion bombardment. in this study the metastable pphase formed by ion-beam-mixing pprocess is comppared with equilibrium one by arc-melting method by GXRD and XAS. Therfore we studied the fundamental characteristics of charge redistribution uppon alloying and formation of intermetallic comppounds. The multi-layer films were depposited on a wet-oxidized Si(100) substrate by sequential electron beam evapporation at a ppressure of less than 5$\times$10-7 Torr during depposition. These compprise 4 ppairs of Co and ppt layers where thicknesses of each layer were varied in order to change the alloy compposition.

• 한국의학물리학회지:의학물리
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• 제9권1호
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• pp.37-46
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• 1998

Beta-particle energy distributions of the radionuclides in medicine are calculated for the medical physics applications. The radial component solutions of Dirac wave equations are evaluated for a point-nucleus un screened Coulomb potential. The WKB method is employed to correct the screening due to the orbital-electron cloud. Fierz interference terms are ignored. The radionuclides considered are $\^$32/P, $\^$90/Y, $\^$131/I, $\^$166/Ho, $\^$192/Ir, $\^$198/Au, $\^$153/Sm, $\^$169/Er and $\^$188/Re. A total of 9 beta-spectra for the radionuclides, currently in domestic use or potential use in the near future, are calculated with enough accuracy and presented in graphs and tables.

• 한국지구과학회지
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• 제18권6호
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• pp.553-558
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• 1997

등축정계의 결정구조를 지니는 무색 투명한 저코니아($Zr_{0.73}Y_{0.27}O_{1.87}$) 결정을 $Y_2O_3$를 안정제로 사용하여 Bridgman-Stockbager법(또는 Skull 용융법)으로 합성하였다. 육성된 결정은 유리광택을 나타내며 동시에 약간의 지방 광택도 띤다. 저코니아 결정은 편광현미경하에서 등방성을 나타내며 이방성의 징후는 발견되지 않는다. 모스 경도는 $8{\sim}8\frac{1}{2}$이고 비중은 5.85이다. 자외선하에서는 약한 백색 형광을 낸다. 단결정법으로 결정한 저코니아의 결정구조는 등축정계이며, 공간군은 $Fm3m({O^5}_h)$이다. 단위포 상수(a)는 $5.1552(5){\AA}$이며, $V=136.99(5){\AA}$, Z=4, R=0.0488이다. 저코니움 원자는 각 모서리에 산소 원자가 자리잡고 있는 육면체의 중심에 위치하고 있으며, 각 산소 원자는 저코니움 원자로 되어 있는 사면체의 중심에 위치하고 있다. 결국 8:4의 배위수가 성립하는 구조를 하고 있다.

• Journal of Magnetics
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• 제5권4호
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• pp.135-138
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• 2000

In order to study the effect of the magnetic anisotropy on the giant magnetoresistance in a Co/Cu multilayered system, the angle dependent magnetoresistance (MR) was measured. The experimental results showed that the maximum MR ratio depends on the angle between the direction of the applied field and the easy axis. The angular modulation of the MR ratio can be explained by the alignments of the two 'effective' magnetization vectors that are bound to their own easy axes. Two maxima observed in MR loops at the second antiferromagnetic maximum are discussed in relation to the magnetic anisotropy, The simulated results under the assumption of the existence of two in-plane easy axes in the sample are compared with the experiments.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.307-314
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• 2000

In order to study the effect of the magnetic anisotropy on the giant magnetoresistance (GMR), the angle dependent magnetoresistance (MR) was measured. The experimental results show that the maximum MR ratio depends on the angle between the direction of the applied field and that of the easy axis. The angular modulation of the MR ratio can be explained by the alignments of the two 'effective' magnetization vectors that are bound to their own easy axes. The typical property of MR loops at 2$\^$nd/ antiferromangtic maximum (AFM) such as two maxima was discussed in relation with the magnetic anisotropy (MA). The simulated results under an assumption of the two in-plane easy axes, which exist in the sample, were compared with the experiments.

• Nuclear Engineering and Technology
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• 제46권2호
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• pp.273-280
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• 2014

The spectrum weighted responses of various detectors were calculated to provide guidance on the proper selection and use of survey instruments on the basis of their energy response characteristics on the neutron fields. To yield the spectrum weighted response, the detector response functions of 17 neutron-measuring devices were numerically folded with each of the produced calibration neutron spectra through the in-house developed software 'K-SWR'. The detectors' response functions were taken from the IAEA Technical Reports Series No. 403 (TRS-403). The reference neutron fields of 21 kinds with 2 spectra groups with different proportions of thermal and fast neutrons have been produced using neutrons from the $^{241}Am$-Be sources held in a graphite pile, a bare $^{241}Am$-Be source, and a DT neutron generator. Fluence-average energy ($E_{ave}$) varied from 3.8 MeV to 16.9 MeV, and the ambient-dose-equivalent rate [$H^*(10)/h$] varied from 0.99 to 16.5 mSv/h.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제16회 학술발표회 논문개요집
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• pp.121-121
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• 1998

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.145.4-145
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• 1998