• Journal of the Korean Magnetics Society
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• v.15 no.1
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• pp.21-24
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• 2005

This work is to present each properties and the interfacial characterization between PZT layer and LSMO layer of PZT/LSMO/Pt. LSMO thin film grown by KrF(248 nm) excimer lasers are used in pulsed in pulsed laser deposition(PLD). PZT coposites thin films were deposited by spin coating using a commercial resist spinner. LSMO thin film by deposition oxygen pressure 125 mtorr have rhombohedral structure on Pt(111) substrate. The PZT/LSM/Pt pre-orientate to [111] direction. The final thin films were shown that magnetic and electric property was typical value, respective. We report that the lattice between the PZT/LSMO thin film and the substrate plays a very important role and may control to another effects.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.2
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• pp.111-116
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• 2012

Na promoted Pt/$CeO_2$ catalysts with various Na amounts (1, 2, and 3wt%) have been applied to water gas shift reaction (WGS) at a gas hourly space velocity (GHSV) of 45515 $h^{-1}$. 1wt%Pt-2wt%Na/$CeO_2$ catalyst exhibited the highest WGS activity at $240^{\circ}C$ among the catalysts prepared in this study. In addition, 1wt%Pt-2wt%Na/$CeO_2$ catalyst showed relatively stable activity with time on stream. The high activity/stability of 1wt%Pt-2wt%Na/$CeO_2$ catalyst was correlated to its easier reducibility and higher oxygen storage capacity (OSC). As a result, 2wt% Na promoted Pt/$CeO_2$ can be a promising candidate catalyst for the single stage WGS, which requires high intrinsic activity at very high GHSV.

• Journal of the Korean Magnetics Society
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• v.11 no.2
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• pp.72-77
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• 2001

Top spin valve films with PtMn antiferromagnetic layers were deposited using a multi-target dc magnetron sputtering in (100)Si substrates overcoated with 500 $\AA$ of Al$_2$O$_3$. Firstly, the post-deposition annealing was performed at 270$\^{C}$ in a unidirectional magnetic field of 3 kOe to induce the crystallographic transformation of the PtMn layer from a fcc (111) to a fct (111) structure. Secondly, the spin valve films were annealed without magnetic fields and magnetic properties were measured. In Si/A1$_2$O$_3$ (500$\AA$)/Ta(50$\AA$)NiFe(40$\AA$)/CoFe(17$\AA$)/Cu(28$\AA$)/CoFe (30$\AA$)PtMn(200$\AA$)Ta(50$\AA$) top spin valve samples, the MR ratio decreased slowly with increasing annealing temperature up to 325$\^{C}$. But above 325$\^{C}$, the MR ratio decreased rapidly to 1%, due to a collapse of the exchange coupling between a antiferromagnetic layer and a pinned layer with increasing annealing temperature. Also above 325$\^{C}$, the exchange biased field rapidly decreased and the interlayer coupling field rapidly increased with increasing annealing temperature. A change in the interlayer coupling field was resulted from the increase in interface roughness due to Mn-interdiffusion through the grain boundaries. We confirmed the temperature in changing magnetic properties agreed well with the blocking temperature of PtMn based spin valve structure.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.735-739
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• 2005

Presented is a voltammetric study of co-adsorption of irreversibly adsorbing Sb and Te on Pt(111). When a layer of Sb and Te was formed via simultaneous adsorption, the reduction peak of Te was observed at 0.30 V in the initial cathodic scan. In contrast, sequential adsorption of Sb followed by Te adsorption led to a Te reduction peak at 0.50 V in the initial scan. As the voltammetric scan was continued, in addition, the voltammogram of the simultaneously co-adsorbed layer changed, while that of the sequentially co-adsorbed layer did not. These observations are discussed in terms of formation of a homogeneously mixed layer and a layer consisting of heterogeneously separated domains of Sb and Te. Also, the difference in the adsorption strength of Sb and Te was observed.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.308-311
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• 2015

https://nano.edison.re.kr/에서 제공하는 Linear Combination of Atomic Orbitals 기반 Density Functional Theory 전자구조계산 SW을 이용하여 정렬된 FCC 결정구조의 PtFe와 원자의 배열이 무질서한 PtFe의 산소 발생 반응의 과전압을 알아보았다. 화학 반응에 참여하는 정렬된 FCC PtFe의 표면 방위는 표면 에너지 계산을 통해 (111) 면으로 설정하였다. 과전압 값은 산소 발생 반응의 각 단계의 자유 에너지 변화를 계산하여 양의 반응 에너지이다. 과전압 측정 결과 정렬된 FCC 결정구조의 PtFe와 원자의 배열이 무질서한 PtFe의 과전압은 각 각 0.623875eV, 0.603118eV 이다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.05a
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• pp.111-111
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• 1998

• Journal of the Korean Magnetics Society
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• v.26 no.4
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• pp.129-132
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• 2016

The effect of thermal-nitrification on L1o transfomation in nano-sized FePt particles was studied. As-synthesized FePt nanoparticles by thermal decomposition method have fcc structured phase and their Hc and Ms were 247.34 Oe and 27.308 emu/g, respectively. According to the XRD analysis, phase transformation from fcc (face centered cubic) to fct (face centered tetragonal) structure was revealed by heating under $NH_3+H_2$ mixed-gas atmosphere. Also a slight shift of each (111) peak indicated phase transformation from fcc to fct structure. Hc and Ms of fct FePtN were 1058.2 Oe and 32.718 emu/g, respectively. The nano-sized FePtN magnetic particles synthesized by thermal decomposition method and mixed-gas nitrification are expected for advanced applications such as high density magnetic recording media and biomedical materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.61-61
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• 2010

By using high resolution x-ray photoelectron spectroscopy, we show that inelastic scattering of photoelectron at low temperature (30K~50K) generates two kinds of oxygen species on Pt (111) surface. Intense synchrotron radiation source dissociates oxygen molecules into chemisorbed atomic oxygen and induces the formation of PtO on surface. Estimated coverage of dissociated atomic oxygen is 0.5 ML, suggesting possible formation of p($2{\times}1$) surface structure, while PtO coverage shows saturation coverage of 0.5 ML. Molecular oxygen dosed at 30 K undergoes thermally activated transition from physisorbed to chemisorbed state at around 40K.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.145.1-145
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• 1998

• Proceedings of the Korean Vacuum Society Conference
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• 2002.02a
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• pp.79-79
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• 2002