• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.192-193
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• 2005

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.201-205
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• 2002

The tunneling magnetoresistance (TMR) of a ramp-edge type junction has been studied. The samples with a structure of NiO(60)/Co(10)/NiO(60)/Si$_3$N$_4$(2-6)/NiFe(10) (nm) were prepared by the sputtering and etched by the electron cyclotron (ECR) argon ion milling. Nonlinear I-V characteristics was obtained from a ramp-type tunneling junctions having the dominant difference between zero and ＋90 Oe perpendicular to the junction edge line. The voltage dependence of TMR was stable up to a bias volt of $\pm$10 V with a TMR ratio of about -10%, which may be very peculiar magnetic tunneling properties with asymmetric tunneling process between wedge Co pinned layer and NiFe free layer.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.102-103
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• 2002

LaMnO$_3$에 Ca을 치환한 Mn계 perovskite 구조(ABO3)의 물질에서 초거대자기저항 현상이 발견된 이후 R$_{1-x}$$^{3+}$ A$_{x}$$^{2+}$MnO$_3$(R=La, Nd, Pr: 희토류금속, A=Ca, Sr, Ba, Cd, Pb; 2가 양이온)계의 Mn 산화물의 연구가 고감도 자기 저항 센서와 자기기록 등의 활용가능성을 중심으로 활발히 진행되고 있다. 자기적 특성이 뛰어난 초거대자기저항물질에 대한 미시적인 자성에 대한 연구는 그 메커니즘이 복잡하고 다양한 접근방식에 따른다. (중략)

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.279-282
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• 2004

본 논문에서는 자기저항 센서를 이용하여 자율주행 시스템에서 필요로 하는 자석의 종류에 따른 자계의 특성을 분석하였다 분석결과 거리에 따라 자계의 특성이 변화하고, 자석에 근접할수록 자계의 변화가 급격하게 나타난다. 센서가 자석에서 멀어질수록 지자계의 값에 가까워진다 또한 페라이트자석 보다 네오디뮴 자석의 자계특성이 우수함을 보였다.

• Journal of the Korean Magnetics Society
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• v.11 no.4
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• pp.151-156
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• 2001

Recently many studies on manganese oxides Ln$_{1-x}$A$_{x}$MnO$_3$(Ln=La, Pr, Nd lanthannide; A=Ca, Sr, Ba, Pb +2 ions) reported CMR properties. CMR have been also found in chalcogenide spinels. We have investigated that Ni ion substitutions for Fe ion have effects on CMR properties in chacogenide spinels Ni$_{x}$Fe$_{1-x}$Cr$_2$S$_4$. It was found that with increasing Ni concentration Jahn-Teller distortion was strengthened and Curie temperature T$_{c}$ was increased. CMR properties could be explained with Jahnl-Teller effect, half-metallic electronic structure, and the alignment of magnetic domain due to the strong magnetic field, which is different in that double exchange interactions dominate CMR properties in manganese oxides.

• Journal of the Korean Magnetics Society
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• v.18 no.6
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• pp.227-231
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• 2008

Magnetic and structural properties of CoFeZr alloy films as a function of Zr concentration and magnetoresistive properties of spin valves incorporated with amorphous CoFeZr alloy films have been studied. Magnetization and coercivity of CoFeZr alloy films decreased as the Zr content increased. A single amorphous CoFeZr phase was formed when the Zr content is about above 18 at%. Magnetoresistance ratio and exchange coupling field of spin valves with amorphous CoFeZr were reduced slightly as compared with spin valves with CoFe because the resistance of amophous CoFeZr is higher than that of crystalline CoFe. However, the ${\Delta}{\rho}$ of spin valves with amorphous CoFeZr was improved due to reduction of current shunting.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.86-97
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• 2007

For continuous growth and diffusion of internet banking, it is important to investigate user resistance factors to internet banking. This study investigates the effects of individual characteristics, characteristics of internet banking and service quality factors on user resistance to internet banking. Individual characteristics include self-efficacy of computer, self-efficacy of internet banking, attitude to change, and innovative attitude. Characteristics of internet banking include relative advantage, compatibility, complexity, and perceived risk. Service quality was classified as 5 dimensions of SERVQUAL. The results of this study showed that self-efficacy of computer, self-efficacy of internet banking, compatibility, responsiveness, complexity, perceived risk, reliability and empathy had a significant effect on user resistance to internet banking.

• Journal of the Korean Vacuum Society
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• v.20 no.1
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• pp.57-62
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• 2011

We have studied the electrical and magnetic transport properties of tunneling device with FePt magnetic quantum dots. The FePt nanoparticles with a diameter of 8~15 nm were embedded in a $SiO_2$ layer through thermal annealing process at temperature of $800^{\circ}C$ in $N_2$ gas ambient. The electrical properties of the tunneling device were characterized by current-voltage (I-V) measurements under the perpendicular magnetic fields at various temperatures. The nonlinear I-V curves appeared at 20 K, and then it was explained as a conductance blockade by the electron hopping model and tunneling effect through the quantum dots. It was measured also that the negative magneto-resistance ratio increased about 26.2% as increasing external magnetic field up to 9,000 G without regard for an applied electric voltage.

• Journal of the Korean Magnetics Society
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• v.8 no.1
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• pp.27-33
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• 1998

We have investigated tunneling magnetoresistance (TMR) properties of Fe/$Al_2O_3$/Co magnetic trilayer junctions sputtered on single-crystal Si (001) substrates. $Al_2O_3$ layers with thicknesses of 50~200 $\AA$ were deposited directly on the bottom ferromagnetic layer by a reactive rf sputtering. For comparsion, we prepared Pt/$Al_2O_3$/Pt tunnel junctions whose current-voltage (I-V) characteristics measured at 300 K indicated that reactively sputtered $Al_2O_3$ is a particularly good material for thin insulating barriers and allows us to form pinhole-free tunnel barriers. The magnetic tunnel junctions exhibit changes of tunnel resistance of about 0.1% at 300 K with an applied magnetic field and it was found that most junctions with Co as a top electrode have rather good I-V and TMR characteristics compared to those with Fe as a electrode. These results were discussed in relation to interfacial on the basis of those for Pt/$Al_2O_3$/Pt.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.129-130
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• 2004