• 제목/요약/키워드: Spintronics

검색결과 200건 처리시간 0.031초

Circuit Components Based on New Materials: The Reality of Multitechnology System on Systems Hyperintegration

  • Eshraghian, Kamran;Cho, Kyoung-Rok
    • Transactions on Electrical and Electronic Materials
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    • 제11권3호
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    • pp.106-111
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    • 2010
  • The convergence of significantly different and disparate technologies such as spintronics, carbon nano tube field effect transistors, photon and bio-responsive molecular switches, memristor and memristive systems and metamaterials, coupled with energy scavenging sources are gaining a renewed focus in the quest for new products. This paper will provide an insight into an anticipated technological revolution and will highlight a futuristic Roadmap to capture opportunities that are brought about as the results of formulation of new circuit components basically driven by emergence of nanoscale materials as part of System on System integration. Challenges as the result of new lumped components such as memristor, metamaterial-based lumped components and the like that will challenge the designers' comfort zone will also be discussed.

Ab initio calculation of half-metallic ferrocene-based nanowire

  • Kim, Seongmin;Park, Changhwi
    • EDISON SW 활용 경진대회 논문집
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    • 제3회(2014년)
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    • pp.425-429
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    • 2014
  • Half-metallic nanostructure is highly applicable in the field of Spintronics and electronic device technology. We examine the electronic properties of a ferrocene-based nanowire as a possible candidate for a half-metallic nanostructure using VASP and SIESTA. Ferrocene-based nanowire shows high stability in both binding energy simulation and molecular dynamics (MD) simulation. The density of states (DOS) and the projected DOS of the ferrocene-based nanowire indicate that one-dimensional clustering of ferrocene molecules can be explained because of p-d orbital hybridization between iron and carbon. Half-metallic property and energy dispersion at the Fermi level due to one-dimensional structure is also observed from the DOS results.

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Negative Dynamic Resistance and RF Amplification in Magnetic Tunnel Junctions

  • Tomita, Hiroyuki;Maehara, Hiroki;Nozaki, Takayuki;Suzuki, Yoshishige
    • Journal of Magnetics
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    • 제16권2호
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    • pp.140-144
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    • 2011
  • We report on a numerical calculation study of two new functional properties in magnetic tunnel junctions (MTJs), negative dynamic resistance and RF amplification. The magnetic dynamics in a conventional CoFeB/MgO/CoFeB MTJ with in-plane magnetization was investigated using a macro-spin model simulation. To examine the influence of thermal fluctuations, random external magnetic fields were also included. Using a voltage controlled bias circuit, the negative dynamic resistance was obtained from time averaged I-V characteristics at both 0 K and 300 K under appropriate external magnetic fields and bias voltages. Using this negative dynamic resistance property, we demonstrated RF amplification with a 100 MHz high frequency signal. Sizable RF amplification gain was observed without thermal fluctuation. However, at 300 K, the RF signal was not amplified because low frequency magnetization dynamics were dominant.

Interface Engineering in Quasi-Magnetic Tunnel Junctions with an Organic Barrier

  • Choi, Deung-Jang;Lee, Nyun-Jong;Kim, Tae-Hee
    • Journal of Magnetics
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    • 제15권4호
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    • pp.185-189
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    • 2010
  • Spin polarized tunneling through a hybrid tunnel barrier of a Spin filter (SF) based on a EuO ferro-magnetic semiconductor and an organic semiconductor (OSC) (rubrene in this case) was investigated. For quasi-magnetic tunnel junction (MTJ) structures, such as Co/rubrene/EuO/Al, we observed a strong spin filtering effect of the EuO layer exhibiting I-V curves with high spin polarization (P) of up to 99% measured at 4 K. However, a magnetoresistance (MR) value of 9% was obtained at 4.2 K. The low MR compared to the high P could be attributed to spin scattering caused by structural defects at the interface between the EuO and rubrene, due to nonstoichiometry in the EuO.

Electromagnetic Resonant Tunneling System: Double-Magnetic Barriers

  • Kim, Nammee
    • Applied Science and Convergence Technology
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    • 제23권3호
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    • pp.128-133
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    • 2014
  • We study the ballistic spin transport properties in a two-dimensional electron gas system in the presence of magnetic barriers using a transfer matrix method. We concentrate on the size-effect of the magnetic barriers parallel to a two-dimensional electron gas plane. We calculate the transmission probability of the ballistic spin transport in the magnetic barrier structure while varying the width of the magnetic barriers. It is shown that resonant tunneling oscillation is affected by the width and height of the magnetic barriers sensitively as well as by the inter-spacing of the barriers. We also consider the effect of additional electrostatic modulation on the top of the magnetic barriers, which could enhance the current spin polarization. Because all-semiconductor-based devices are free from the resistance mismatch problem, a resonant tunneling structure using the two-dimensional electron gas system with electric-magnetic modulation would play an important role in future spintronics applications. From the results here, we provide information on the physical parameters of a device to produce well-defined spin-polarized current.

Unidirectional motion of bubble domains in magnetic film

  • Moon, Kyoung-Woong;Kim, Duck-Ho;Yoo, Sang-Cheol;Je, Soong-Geun;Chun, Byong Sun;Kim, Wondong;Min, Byoung-Chul;Hwang, Chanyong;Choe, Sug-Bong
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2014년도 자성 및 자성재료 국제학술대회
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    • pp.49-49
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    • 2014
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Using Electron-beam Resists as Ion Milling Mask for Fabrication of Spin Transfer Devices

  • Nguyen Hoang Yen Thi;Yi, Hyun-Jung;Shin, Kyung-Ho
    • Journal of Magnetics
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    • 제12권1호
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    • pp.12-16
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    • 2007
  • Magnetic excitation and reversal by a spin polarized current via spin transfer have been a central research topic in spintronics due to its application potential. Special techniques are required to fabricate nano-scale magnetic layers in which the effect can be observed and studied. This work discusses the possibility of using electron-beam resists, the nano-scale patterning media, as ion milling mask in a subtractive fabrication method. The possibility is demonstrated by two resists, one positive tone, the ZEP 520A, and one negative tone, the ma-N2403. The advantage and the key points for success of this process will be also addressed.