• Title/Summary/Keyword: spin-structure

Search Result 727, Processing Time 0.026 seconds

The Structure, and the Magnetic and Magnetoresistive Characteristics of the Spin Valve Multilayers

  • Stobiecki, T.;Czapkiewicz, M.;Wrona, J.;Powroynik, W.;Stobiecki, F.
    • Journal of Magnetics
    • /
    • v.3 no.3
    • /
    • pp.92-95
    • /
    • 1998
  • In this paper we report the low and high angle diffraction results, and the magnetic and magnetroesistive characteristics of the spin valve multilayer structure prepared by the sputter machine Emerald II in the Balzers Laboratory. The investigated system consists of a ferromagnetic free layer (7 nm NiFe) and a ferromagnetic pinned layer (7 nm NiFe), separated from each other by a nonmagnetic (2.1 nm Cu) spacer. The NiFe pinned layer is fixed by the exchange coupling with an antiferromagnetic layer (10 nm FeMn). For such system the magnetoresistance ratio ΔR/R=3.58%, the interlayer exchange coupling $H_c=6.4$ Oe and the field sensitivity 1.15%/Oe were otained.

  • PDF

Biracial Silicon Solar Cells with Spin-on Doping and Electroless Plating

  • U. Gangopadhyay;Kim, Kyung-Hae;S.K. Dhungel;D. Mangalaraj;Park, J.H.;J. Yi
    • Transactions on Electrical and Electronic Materials
    • /
    • v.5 no.1
    • /
    • pp.7-10
    • /
    • 2004
  • A new method for fabrication of transistor like structure of the bifacial solar cell using spin-on doping and electroless plating has been proposed and the basic characteristics of the bifacial cell have been investigated. It is found that 9% increase in short circuit current is achieved with bifacial connection than the unifacial connection. Some unwanted effect of the series resistance on collection efficiency under different mode of illumination has been pointed out. Loss mechanisms inherent in the transistor like bifacial structure have also been discussed.

FIRST PRINCIPLE CALCULATIONS OF MCD SPECTRA FOR SANDWICHED Co(110) SYSTEMS

  • Hong, Soon-C.;Lee, Jae-Il;Wu, R.;Freeman, A.J.
    • Journal of the Korean Magnetics Society
    • /
    • v.5 no.5
    • /
    • pp.575-578
    • /
    • 1995
  • X-ray magnetic-circular-dichroism (MCD) spectra, orbital ($$) and spin magnetic moments ($$) for Co(110) monolayers a free standing mode or sandwiched between Pd(Pd/1Co/Pd)and Cu layers (Cu/1Co/Cu) are calculated using the thin film full potential linearized augmented plane wave energy band method. In contrast to the double peak structure predicted for the Co(0001) surface, only a minor side peak is found in the MCD spectra for Cu/Co/Cu, while MCD spectra for the other systems show a single peak structure. The MCD sum rules originally derived from a single ion model are found in the band approach to be valid for the systems investigated. However, for the spin sum rule, the magnetic dipole term ($$) is not negligible and needs to be included.

  • PDF

Effects of Precursor on the Electrical Properties of Spin-on Dielectric Films (Spin-on Dielectric 막의 전기적 특성에 미치는 전구체의 영향)

  • Lee, Wan-Gyu
    • Korean Journal of Materials Research
    • /
    • v.21 no.4
    • /
    • pp.236-241
    • /
    • 2011
  • Polysilazane and silazane-based precursor films were deposited on stacked TiN/Ti/TEOS/Si-substrate by spin-coating, then annealed at $150{\sim}400^{\circ}C$, integrated further to form the top electrode and pad, and finally characterized. The precursor solutions were composed of 20% perhydro-polysilazane ($SiH_2NH$)n, and 20% hydropolymethyl silazane ($SiHCH_3NH$)n in dibutyl ether. Annealing of the precursor films led to the compositional change of the two chemicals into silicon (di)oxides, which was confirmed by Fourier transform infrared spectroscopy (FTIR) spectra. It is thought that the different results that were obtained originated from the fact that the two precursors, despite having the same synthetic route and annealing conditions, had different chemical properties. Electrical measurement indicated that under 0.6MV/cm, a larger capacitance of $2.776{\times}10^{-11}$ F and a lower leakage current of 0.4 pA were obtained from the polysilazane-based dielectric films, as compared to $9.457{\times}10^{-12}$ F and 2.4 pA from the silazane-based film, thus producing a higher dielectric constant of 5.48 compared to 3.96. FTIR indicated that these superior electrical properties are directly correlated to the amount of Si-O bonds and the improved chemical bonding structures of the spin-on dielectric films, which were derived from a precursor without C. The chemical properties of the precursor films affected both the formation and the electrical properties of the spin-on dielectric film.

The Fabrication and Magnetoresistance of Nanometer-sized Spin Device Driven by Current Perpendicular to the Plane (수직전류 인가형 나노 스핀소자의 제조 및 자기저항 특성)

  • Chun, M.G.;Lee, H.J.;Jeung, W.Y.;Kim, K.Y.;Kim, C.G.
    • Journal of the Korean Magnetics Society
    • /
    • v.15 no.2
    • /
    • pp.61-66
    • /
    • 2005
  • In order to make submicron cell for spin-injection device, lift-off method using Pt stencil and wet etching was chosen. This approach allows batch fabrication of stencil substrate with electron-beam lithography. It simplifies the process between magnetic film stack deposition and final device testing, thus enabling rapid turnaround in sample fabrication. Submicron junctions with size of $200nm{\times}300nm$ and $500nm{\times}500nm$ 500 nm and pseudo spin valve structure of $CoFe(30{\AA})/Cu(100{\AA})/CoFe(120{\AA}$) was deposited into the nanojunctions. MR ratio was 0.8 and $1.1{\%}$, respectively and spin transfer effect was confirmed with critical current of $7.65{\times}10^7A/cm^2$.

Preparation and Properties of Poly(vinylidene fluoride) Multilayer Films (Poly(vinylidene fluoride) 다층 필름의 제조 및 특성)

  • Son, Tae-Won;Kim, Jong-Hwan;Choi, Won-Mi;Han, Fei-Fei;Kwon, Oh-Kyeong
    • Polymer(Korea)
    • /
    • v.35 no.2
    • /
    • pp.130-135
    • /
    • 2011
  • Along with the fast development of electronics, the demands of portable electronics and wireless sensors are growing rapidly. The need for self-powering materials capable of powering the electrical devices attached to them is increasing, The piezoelectric effect of polyvinylidene fluoride (PVDF) can be used for this purpose. PVDF has a special crystal structure consisting of a ${\beta}$-phase that can produce piezoelectricity. In this paper, multilayer PVDF films were fabricated to increase the ${\beta}$-phase content. A solution of 10% concentration N;N-dimethylacetamide (DMAc) in PVDF (PVDF/DMAc) was used to fabricate the films via spin coating technique with the following optimum process parameters: a spin rate of 850 rpm, spin time of 60 s, drying temperature of $60^{\circ}C$, and drying time of 30 min, Compared with single-layer PVDF films, the multilayer films exhibited higher ${\beta}$-phase content. The ${\beta}$-phase content of the films increased gradually with increasing number of layers until 4, Maximum ratio of ${\beta}$-phase content was 7.72.

Control effects of the flow and the aerodynamic force around the downstream cylinder by a spinning upstream cylinder in uniform flow (균일류의 회전원주 제어에 의한 유동 및 공력 제어효과에 관한 연구)

  • Bu, Jeong-Suk;Yang, Jong-Pil;Kim, Chang-Su;Sin, Yeong-Gon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.22 no.3
    • /
    • pp.346-359
    • /
    • 1998
  • The aerodynamic forces and wake structure of the non-rotating downstream circular cylinder, of which the uniform freestream flow is interfered with another spinning upstream cylinder having the same diameter that is located upstream in a line have been investigated experimentally. When the spin rate of the downstream cylinder defined as the ratio of tangential surface velocity of the spinning cylinder to the freestream velocity increases gradually from zero to 1.4, the change of surface pressure distribution, aerodynamic forces of the non-rotating downstream cylinder were measured in case of several distance ratios of 1.5, 3.0, and 4.5 defined as the ratio of distance between the centers of two cylinders to the diameter. The wake flow patterns behind the cylinder were also investigated in each case. From the present experiments, it has been found that the spin rate significantly influences the aerodynamic forces and near-wake flow phenomena of the downstream cylinder in such a way that the drag increases as the spin rate and distance ratio increase and the wake width increases as the distance ratio increases.

Effects of the Hard-Biased Field on the Magnetic and Magnetoresistive Properties of a Crossed Spin-Valve Bead by Computer Simulation

  • S. H. Lim;K. H. Shin;Kim, K. Y.;S. H. Han;Kim, H. J.
    • Journal of Magnetics
    • /
    • v.5 no.1
    • /
    • pp.19-22
    • /
    • 2000
  • The effects of a hard-biased Held on the magnetic and magnetoresistive properties of a crossed spin-valve head are investigated by computer simulation with particular emphasis on the asymmetry of the output signal. The spin-valve considered in this work is NiMn (25 nm)/NiFe (2.5 m)/Cu (3 nm)/NiFe (5.5 m), with a length of 1500 m and a width of 600 nm. A simple model is used where each magnetic layer consists of a single domain, and the magnetoresistance is a function of the angle between the magnetization directions of the two magnetic layers. The ideal crossed spin-valve structure is not realized with the present model and magnetic parameters, but the deviation from ideality is decreased by the hard-biased field. This results in the improvement of the linearity of the output signal with the use of the bias field. The magnetoresistance ratio and magnetoresistive sensitivity, however are reduced. The magnetic properties including the magnetoresistance are found to be strongly affected by magnetostatic interactions, particularly the inter-layer magnetostatic field.

  • PDF

A Study about The Spin-off Phenomenon of Brand Webtoon Storytelling (브랜드 웹툰 스토리텔링의 스핀오프 양상 연구)