• 한국자기학회:학술대회 개요집
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• 한국자기학회 2005년도 동계학술연구발표회 및 2차 아시안포럼
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• pp.206-207
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• 2005

• 해양환경안전학회지
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• 제14권1호
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• pp.39-43
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• 2008

해양환경 오염에 대한 관심이 많아지면서 해양환경 인자에 대한 감시가 그 중요성을 더해 가고 있다. 지금까지는 이에 대한 감지를 위한 센서의 부재로 인하여 해수를 채취하여 실험실에서 고가의 장비를 이용하여 분석하여 왔다. 이는 해양의 실시간 감시가 어려울 뿐 아니라 급변하는 해양 상태를 정확하게 파악하기 어려운 면이 있어왔다. 이러한 단점을 보완하기위해서 나노기술을 이용한 해양용 센서 개발이 시급히 요구되는 바 이에 대한 기술적인 분야와 특징 및 타당성을 검토하였다 현재 기술적으로 개발이 가능하고 국제적으로 경쟁력이 있는 분야로는 나노스핀소자를 이용한 바이오분자 감지, 탄소나노튜브의 전도성 변화에 따른 해양인자 감시기술, 그리고 나노반도체를 이용한 적조관련 미생물 감지 기술을 제시하였다. 이 기술들의 특징과 해양환경에서의 적용을 위하여 개발하여야 할 요소 기술을 찾아보고 문제점들을 극복할 수 있는 방안을 제시하였다.

• Journal of Magnetics
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• 제10권2호
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• pp.48-51
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• 2005

The spin transfer induced magnetization switching has been reported to occur in magnetic multilayer structures whose scope usually consists of one stack of ferromagnetic / non-ferromagnetic / ferromagnetic (F / N / F) materials. In this work, it is shown that: 1) Copper used as a buffer layer between the free Co and the Au cap-layer can clearly increase the probability to get the spin transfer induced magnetization switching in a simple spin valve Co 11 / Cu 6/ Co 2 (nm); 2) Furthermore, when Ruthenium is simultaneously applied as a buffer layer on the Si-substrate, the critical switching currents can be reduced by $30\%$, and the absolute resistance change delta R $[{\Delta}R]$ of that stack can be enlarged by $35\%$. The enhancement of the spin transfer induced magnetization switching can be ascribed to a lower local stress in the thin Co layer caused by a better lattice match between Co and Cu and the smoothening effect of Ru on the thick Co layer.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.183-183
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• 2014

Recently, multiferroic materials gain much attention due to their fascinating fundamental physical properties. These materials offer wide range of potential applications such as data storage, spintronic devices and sensors, where both electronic and magnetic polarizations can be coupled. Among single-phase multiferroic materials, $BiFeO_3$ is typical because of the room-temperature magnetoelectric coupling in view of long-range magnetic- and ferroelectric-ordering temperatures. However, $BiFeO_3$ is well known to have large leakage current and small spontaneous polarization due to the existence of oxygen vacancies and other defects. Furthermore the magnetic moment of pure $BiFeO_3$ is very weak owing to its antiferromagnetic nature. Recently, various attempts have been performed to improve the multiferroic properties of $BiFeO_3$ through the co-doping at the A and the B sites, by making use of the fact that the intrinsic polarization and magnetization are associated with the lone pair of $Bi^{3+}$ ions at the A sites and the partially-filled 3d orbitals of $Fe^{3+}$ ions at the B sites, respectively. In this study, $BiFeO_3$, $Bi_{0.9}Ho_{0.1}FeO_3$, $BiFe_{0.97}Ni_{0.03}O_3$ and $Bi_{0.9}Ho_{0.1}Fe_{0.97}Ni_{0.03}O_3$ bulk compounds were prepared by solid-state reaction and rapid sintering. High-purity $Bi_2O_3$, $Ho_2O_3$, $Fe_2O_3$ and $NiO_2$ powders with the stoichiometric proportions were mixed, and calcined at $500^{\circ}C$ for 24 h to produce the samples. The samples were immediately put into an oven, which was heated up to $800^{\circ}C$ and sintered in air for 1 h. The crystalline structure of samples was investigated at room temperature by using a Rigaku Miniflex powder diffractometer. The field-dependent and temperature-dependent magnetization measurements were performed with a vibrating-sample magnetometer and superconducting quantum-interference device.