The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

J Grenzer - One of the best experts on this subject based on the ideXlab platform.

  • revisiting Magnetic Stripe domains anisotropy gradient and Stripe asymmetry
    Journal of Applied Physics, 2013
    Co-Authors: J Mccord, Burak Erkartal, Thomas Von Hofe, Lorenz Kienle, Eckhard Quandt, Olga Roshchupkina, J Grenzer
    Abstract:

    The thickness dependent generation of Magnetic Stripe domains in NiFe films is investigated by in-depth Magnetic domain and microMagnetic analysis, as well as complementary analysis of the microstructure by x-ray diffraction and transmission electron microscopy. A gradient of perpendicular Magnetic anisotropy with film thickness is found. MicroMagnetic simulations show that the anisotropy gradient results in an asymmetric Stripe domain configuration. Columnar grain coarsening and texture development with thickness are derived from the microstructural investigations. The variations correspondingly lead to the gradient of Magnetic anisotropy and to an asymmetric Magnetic Stripe domain structure.

  • Revisiting Magnetic Stripe domains — anisotropy gradient and Stripe asymmetry
    Journal of Applied Physics, 2013
    Co-Authors: J Mccord, Burak Erkartal, Thomas Von Hofe, Lorenz Kienle, Eckhard Quandt, Olga Roshchupkina, J Grenzer
    Abstract:

    The thickness dependent generation of Magnetic Stripe domains in NiFe films is investigated by in-depth Magnetic domain and microMagnetic analysis, as well as complementary analysis of the microstructure by x-ray diffraction and transmission electron microscopy. A gradient of perpendicular Magnetic anisotropy with film thickness is found. MicroMagnetic simulations show that the anisotropy gradient results in an asymmetric Stripe domain configuration. Columnar grain coarsening and texture development with thickness are derived from the microstructural investigations. The variations correspondingly lead to the gradient of Magnetic anisotropy and to an asymmetric Magnetic Stripe domain structure.

Bodhi Priyantha - One of the best experts on this subject based on the ideXlab platform.

  • Unleashing the Wild Card for mobile payment
    2014 IEEE International Conference on Pervasive Computing and Communications (PerCom), 2014
    Co-Authors: Mastooreh Salajegheh, Bodhi Priyantha
    Abstract:

    Mobile wallets promise a future where users do not need to carry physical payment cards. However, the slow adoption of contactless point of sales (POS) terminals by merchants limits the potential of Near-Field Communication (NFC) based payment devices. In this paper, we present Wild Card, a secure and backward compatible solution for making mobile payments at conventional Magnetic Stripe based POS terminals. Our solution resembles a traditional credit card in its physical dimensions and stays in the phone case. It can be programmatically set by an NFC-enabled mobile phone to any card number that the user owns. The key technologies that enable Wild Card are a fully programmable Magnetic Stripe, an energy harvesting system that allows the card to be charged and programmed by the phone through NFC, and a security mechanism that makes card information resilient to attacks on mobile devices. With a prototype, we evaluate the feasibility of Wild Card in terms of functionality and energy budget.

  • PerCom - Unleashing the Wild Card for mobile payment
    2014 IEEE International Conference on Pervasive Computing and Communications (PerCom), 2014
    Co-Authors: Mastooreh Salajegheh, Bodhi Priyantha
    Abstract:

    Mobile wallets promise a future where users do not need to carry physical payment cards. However, the slow adoption of contactless point of sales (POS) terminals by merchants limits the potential of Near-Field Communication (NFC) based payment devices. In this paper, we present Wild Card, a secure and backward compatible solution for making mobile payments at conventional Magnetic Stripe based POS terminals. Our solution resembles a traditional credit card in its physical dimensions and stays in the phone case. It can be programmatically set by an NFC-enabled mobile phone to any card number that the user owns. The key technologies that enable Wild Card are a fully programmable Magnetic Stripe, an energy harvesting system that allows the card to be charged and programmed by the phone through NFC, and a security mechanism that makes card information resilient to attacks on mobile devices. With a prototype, we evaluate the feasibility of Wild Card in terms of functionality and energy budget.

J Mccord - One of the best experts on this subject based on the ideXlab platform.

  • revisiting Magnetic Stripe domains anisotropy gradient and Stripe asymmetry
    Journal of Applied Physics, 2013
    Co-Authors: J Mccord, Burak Erkartal, Thomas Von Hofe, Lorenz Kienle, Eckhard Quandt, Olga Roshchupkina, J Grenzer
    Abstract:

    The thickness dependent generation of Magnetic Stripe domains in NiFe films is investigated by in-depth Magnetic domain and microMagnetic analysis, as well as complementary analysis of the microstructure by x-ray diffraction and transmission electron microscopy. A gradient of perpendicular Magnetic anisotropy with film thickness is found. MicroMagnetic simulations show that the anisotropy gradient results in an asymmetric Stripe domain configuration. Columnar grain coarsening and texture development with thickness are derived from the microstructural investigations. The variations correspondingly lead to the gradient of Magnetic anisotropy and to an asymmetric Magnetic Stripe domain structure.

  • Revisiting Magnetic Stripe domains — anisotropy gradient and Stripe asymmetry
    Journal of Applied Physics, 2013
    Co-Authors: J Mccord, Burak Erkartal, Thomas Von Hofe, Lorenz Kienle, Eckhard Quandt, Olga Roshchupkina, J Grenzer
    Abstract:

    The thickness dependent generation of Magnetic Stripe domains in NiFe films is investigated by in-depth Magnetic domain and microMagnetic analysis, as well as complementary analysis of the microstructure by x-ray diffraction and transmission electron microscopy. A gradient of perpendicular Magnetic anisotropy with film thickness is found. MicroMagnetic simulations show that the anisotropy gradient results in an asymmetric Stripe domain configuration. Columnar grain coarsening and texture development with thickness are derived from the microstructural investigations. The variations correspondingly lead to the gradient of Magnetic anisotropy and to an asymmetric Magnetic Stripe domain structure.

M Marangolo - One of the best experts on this subject based on the ideXlab platform.

  • Perpendicular Magnetic Anisotropy in Fe–N Thin Films: Threshold Field for Irreversible Magnetic Stripe Domain Rotation
    SPIN, 2020
    Co-Authors: L C Garnier, D Bisero, F Fortuna, V H Etgens, M. Eddrief, M Marangolo
    Abstract:

    The Magnetic properties of an iron nitride thin film obtained by ion implantation have been investigated. N[Formula: see text] ions were implanted in a pristine iron layer epitaxially grown on ZnSe/GaAs(001). X-ray diffraction measurements revealed the formation of body-centered tetragonal N-martensite whose [Formula: see text]-axis is perpendicular to the thin film plane and [Formula: see text]-parameter is close to that of [Formula: see text]-Fe8N. Magnetic measurements disclosed a weak perpendicular Magnetic anisotropy (PMA) whose energy density [Formula: see text] was assessed to about 105[Formula: see text]J/m3. A sharp decline of the in-plane magnetocrystalline anisotropy (MCA) was also observed, in comparison with the body-centered cubic iron. The origin of the PMA is attributed to the MCA of N-martensite and/or stress-induced anisotropy. As a result of the PMA, weak Magnetic Stripe domains with a period of about 130[Formula: see text]nm aligned along the last saturating Magnetic field direction were observed at remanence by Magnetic force microscopy. The application of an increasing in-plane Magnetic field transverse to the Stripes [Formula: see text] highlighted a threshold value ([Formula: see text][Formula: see text]T) above which these Magnetic domains irreversibly rotated. Interestingly, below this threshold, the Stripes do not rotate, leading to a zero remanent magnetization along the direction of the applied field. The interest of this system for magnetization dynamics is discussed.

  • perpendicular Magnetic anisotropy in fe n thin films threshold field for irreversible Magnetic Stripe domain rotation
    SPIN, 2016
    Co-Authors: L C Garnier, D Bisero, M Eddrief, F Fortuna, V H Etgens, M Marangolo
    Abstract:

    The Magnetic properties of an iron nitride thin film obtained by ion implantation have been investigated. N+22+ ions were implanted in a pristine iron layer epitaxially grown on ZnSe/GaAs(001). X-ray diffraction measurements revealed the formation of body-centered tetragonal N-martensite whose cc-axis is perpendicular to the thin film plane and cc-parameter is close to that of α′α′-Fe8N. Magnetic measurements disclosed a weak perpendicular Magnetic anisotropy (PMA) whose energy density KPMAKPMA was assessed to about 105J/m3. A sharp decline of the in-plane magnetocrystalline anisotropy (MCA) was also observed, in comparison with the body-centered cubic iron. The origin of the PMA is attributed to the MCA of N-martensite and/or stress-induced anisotropy. As a result of the PMA, weak Magnetic Stripe domains with a period of about 130nm aligned along the last saturating Magnetic field direction were observed at remanence by Magnetic force microscopy. The application of an increasing in-plane Magnetic field transverse to the Stripes HtransHtrans highlighted a threshold value (μ0Htrans≈0.1μ0Htrans≈0.1T) above which these Magnetic domains irreversibly rotated. Interestingly, below this threshold, the Stripes do not rotate, leading to a zero remanent magnetization along the direction of the applied field. The interest of this system for magnetization dynamics is discussed.

  • in plane rotation of Magnetic Stripe domains in fe1 xgax thin films
    Physical Review B, 2015
    Co-Authors: R Tomasello, D Bisero, M Marangolo, M Sacchi, Horia Popescu, M Eddrief, C Hepburn, G Finocchio, M Carpentieri, A Rettori
    Abstract:

    The in-plane rotation of Magnetic Stripe domains in a 65-nm magnetostrictive Fe0.8Ga0.2 epitaxial film was investigated combining Magnetic force microscopy, vibration sample magnetometry, and x-ray resonant Magnetic scattering measurements. We analyzed the behavior of the Stripe pattern under the application of a bias Magnetic field along the in-plane direction perpendicular to the Stripe axis, and made a comparison with the analogous behavior at remanence. The experimental results have been explained by means of microMagnetic simulations, supported by energy balance considerations. Fields smaller than ∼400 Oe do not induce any Stripe rotation; rather, a deformation of the closure domains pattern was evidenced. Larger fields produce a sudden rotation of the Stripe structure.

Y Z Wu - One of the best experts on this subject based on the ideXlab platform.

  • Magnetic Stripe melting at the spin reorientation transition in fe ni cu 001
    Physical Review B, 2005
    Co-Authors: Y Z Wu, Andreas Scholl, Andrew Doran, Jong Hyun Choi, T Owens, Jianzhong Wu, Hengcan Zhao
    Abstract:

    Magnetic Stripe domains in Fe/Ni/Cu(001) were imaged andstudied using photoemission electron microscopy. The Stripe domain widthdecreases exponentially as the system approaches the spin reorientationtransition SRT point. A reduction of the Curie temperature TC is observedwithin a narrow gap of the SRT region. For film with fixed thickness, theStripe domains below TC represent only part of the Stripe phase due to ahigher SRT temperature than TC.

  • Magnetic Stripe domains in coupled Magnetic sandwiches
    Physical Review Letters, 2004
    Co-Authors: Y Z Wu, Andreas Scholl, Andrew Doran, H W Zhao
    Abstract:

    : Magnetic Stripe domains in the spin reorientation transition region are investigated in (Fe/Ni)/Cu(001) and Co/Cu/(Fe/Ni)/Cu(001) using photoemission electron microscopy. For (Fe/Ni)/Cu(001), the Stripe domain width decreases exponentially as the Fe/Ni film approaches the spin reorientation transition point. For Co/Cu/(Fe/Ni)/Cu(001), the Fe/Ni Stripe orientation is aligned with the Co in-plane magnetization, and the Stripe domain width decreases exponentially with increasing the interlayer coupling between the Fe/Ni and Co films. By considering Magnetic Stripes within an in-plane Magnetic field, we reveal a universal dependence of the Stripe domain width on the Magnetic anisotropy and on the interlayer coupling.

  • Magnetic Stripe domains in coupled Magnetic sandwiches
    Physics, 2004
    Co-Authors: Y Z Wu, Andreas Scholl, Andrew Doran, H W Zhao
    Abstract:

    Magnetic Stripe domains in the spin reorientation transition region are investigated in (Fe/Ni)/Cu(001) and Co/Cu/(Fe/Ni)/Cu(001) using photoemission electron microscopy. For the former, the Stripe domain width decreases exponentially as the Fe/Ni film approaches the transition point. For the latter, the Fe/Ni Stripe orientation is aligned with the Co in-plane magnetization and the domain width decreases exponentially with increasing of the interlayer coupling between the Fe/Ni and Co films. By considering Magnetic Stripes within an in-plane Magnetic field, we reveal a universal dependence of the Stripe domain width on the Magnetic anisotropy and on the interlayer coupling.