• Title/Summary/Keyword: Tunnel junction

Search Result 220, Processing Time 0.029 seconds

CoFe Layer Thickness and Plasma Oxidation Condition Dependence on Tunnel Magnetoresistance (CoFe의 삽입과 산화조건에 따른 자기 터널 접합의 자기저항특성에 관한 연구)

  • 이성래;박병준
    • Journal of the Korean Magnetics Society
    • /
    • v.11 no.5
    • /
    • pp.196-201
    • /
    • 2001
  • The dependence of CoFe interfacial layer thickness and plasma oxidation condition on tunneling magnetoresistance (TMR) in Ta/NiFe/FeMn/NiFe/Al$_2$O$_3$/NiFe/Ta tunnel junctions was investigated. As the CoFe layer thickness increases, TMR ratio rapidly increases to 13.7 % and decreases with further increase of the CoFe layer thickness. The increase of TMR with the CoFe thickness up to 25 was thought to be due mails to the high spin-polarization of CoFe. The maximum MR of 15.3% was obtained in the Si(100)/Ta(50 )/NiFe(60 )/FeMn(250 )/NiFe(70 )/Al$_2$O$_3$/NiFe(150 )/Ta(50 ) magnetic tunnel junction with a 16 Al oxidized for 40 sec using a Ar/O$_2$ (1:4) mixture gas.

  • PDF

Switching Characteristics of Magnetic Tunnel Junction with Amorphous CoFeSiB Free Layer (비정질 CoFeSiB 자유층을 갖는 자기터널접합의 스위칭 특성)

  • Hwang, J.Y.;Rhee, J.R.
    • Journal of the Korean Magnetics Society
    • /
    • v.16 no.6
    • /
    • pp.276-278
    • /
    • 2006
  • The switching characteristics of magnetic tunnel junctions (MTJs) comprising amorphous ferromagnetic CoFeSiB free layer have been investigated. CoFeSiB was used for the free layer to enhance the switching characteristics. The typical junction structure was $Si/SiO_{2}/Ta$ 45/Ru 9.5/IrMn 10/CoFe $7/AlO_{x}/CoFeSiB\;(t)/Ru\;60\;(in\;nm)$. CoFeSiB has low saturation magnetization ($M_{s}$) of $560\;emu/cm^{3}$ and high anisotropy constant ($K_{u}$) of $2800\;erg/cm^{3}$. These properties caused low coercivity ($H_{c}$) and high sensitivity in MTJs, and it also confirmed in submicrometer-sized elements by micromagnetic simulation based on the Landau-Lisfschitz-Gilbert equation. By increasing CoFeSiB free layer thickness, the switching characteristics became worse due to increase of the demagnetization field.

Simulation Analysis of Spatially Arterial Pulse Wave using Two-dimensional Array Sensors with Magnetoresistive Device (2차원 배열 자기저항소자를 이용한 공간 맥진파형의 전산모사 분석)

  • Kim, M.S.;Kim, S.W.;Kim, G.W.;Lee, S.J.;Lee, S.G.;Lee, H.S.;Park, D.H.;Hwang, D.G.;Lee, S.S.
    • Journal of the Korean Magnetics Society
    • /
    • v.15 no.6
    • /
    • pp.307-310
    • /
    • 2005
  • To get the spatial feature of arterial pulse, we designed spatial pulse diagnostic apparatus (SPDA) using a 2-dimensional magnetoresistive sensor array. The magnetic field distribution fur magnet may was simulated using finite element method. We recognized that the field distribution of parallel magnet mays was more sensitive and uniformed than that of perpendicular one. Also the spatial displacements of magnet array were agreed with the output signal of magnetic tunnel junction (MTJ) sensor array.

Application of seismic reflection method in the tunnel of Youngdong railroad (Mt. Dongbaek~Dokye) (영동선 동백산-도계간 터널내 반사법 탄성파탐사 적용사례)

  • Kim, Yong-Il;Cho, Sang-Kook;Yang, Jong-Hwa;Kim, Jang-Soo;Lee, Nai-Yong
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.5 no.1
    • /
    • pp.89-100
    • /
    • 2003
  • Seismic Reflection Methods (TSP, HSP) have been applied in the junction between 2nd Adit and Main Tunnel (Solan Tunnel) of Youngdiong Railroad (Mt. Dongbaek~Dokye). In this paper, methods and case study will be introduced to predict discontinuties in the tunnel before excavation by the Seismic Reflection Methods (TSP, HSP)and secure construction stability of the tunnel in blasting and excavation.

  • PDF

Spin injection and transport properties of Co/Au/Y$Ba_2$$Cu_3$$O_y$ tunnel junctions

  • Lee, Kiejin;Kim, Sunmi;Ishibashi, Takauki;Cha, Deokjoon
    • Progress in Superconductivity
    • /
    • v.3 no.1
    • /
    • pp.70-73
    • /
    • 2001
  • We report the spin injection and transport properties of three terminal devices of Co/Au/$YBa_2$$Cu_3$$O_{y}$(F/N/S) tunnel junctions by injection of spin-polarized quaiparticles using a cobalt ferromagnetic injector. The observed current gain depends on the thickness of Au interlayer and is directly related to the nonequilibrium magnetization due to spin relaxation effects. The tunnel characteristic of a F/N/S tunnel junctions exhibited a zero bias conductance peak (ZBCP). The suppression of the ZBCP was observed due to the suppression of Andreev reflection at the interface, which is due to the spin scattering processes at the interface between a ferromagnetic and a d-wave superconductor.r.

  • PDF