Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Dependence of the anisotropic magnetoresistance on aspect ratio in cobalt films (abstract) : 38th Annual Conference on Magnetism and Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 6567-6567 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High quality measurements of the anisotropic magnetoresistance, defined as the difference in the resistivities when the saturated sample magnetization is parallel and perpendicular to the current, are performing using four terminal measurements. What is occasionally not considered in these measurements is the geometry of the sample and contacts. This work reports how the anisotropic magnetoresistance (AMR), measured with four in-line point contacts attached to thin film specimens, is affected by the geometry of the films. Cobalt samples were lithographically narrowed in 2 mm steps from 10 mm×10 mm to 2 mm×10 mm. For each of the five sizes, the AMR and resistivity were measured using the four-probe-in-line technique with 3 mm from one contact to the next. The results show that the measured AMR increases by a factor of 2 from the widest to narrowest size. This width dependence of the AMR arises from spreading of the current between the voltage contacts. In order to make an accurate assessment of the AMR, the current across the entire width of the sample must be parallel to the line joining the voltage contacts. Similar work has been performed by A. Iwaide et al., and published in J. Magn. Soc. Jpn. 16, 197 (1992). The results reported in this abstract are in agreement with those in the above-mentioned paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356921
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A comparison of the giant magnetoresistance and anisotropic magnetoresistance in Co/Cu sandwich films (abstract) : The 6th joint magnetism and magnetic materials (MMM)-intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6616-6616 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: By a systematic variation of structures, recent measurements conclude the scattering associated with the high resistance giant magnetoresistance (GMR) state occurs within 0.25 nm of the magnetic interface. We have accomplished a similar measurement that does not require such stringent control of the sample structure. Instead, the present work uses measurements of the anisotropic magnetoresistance (AMR) in both the high resistance and low resistance GMR states. The samples are sandwiches of Co/Cu/Co/CoO with Co thicknesses ranging from 1 to 10 nm and Cu thickness of approximately 2.5 nm. The AMR is measured with the Co magnetizations aligned parallel to one another (the low resistance GMR state) and with the Co magnetizations aligned antiparallel to one another (the high resistance GMR state). The data show that the AMR in the antiparallel configuration is less than that in the parallel configuration. An analysis that relates the reduced AMR to the magnetic interfacial region giving rise to the high resistance GMR state indicates the scattering occurs within approximately 0.5 nm of the interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ex situ CrPtMn pinning and ex situ CrPtMn pinned spin valves (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6594-6596 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ex situ CrPtMn pinned bilayers and ex situ CrPtMn pinned spin valves have been investigated by exploring the correlation between the pinning and deposition process. It was found that exchange coupling is strongly related to the deposition condition. The ex situ deposited CrPtMn can only reliably exchange couple to the NiFeCo (or CoFe) when CrPtMn is deposited on it with an applied magnetic field. The exchange coupling is not seen as a strong function of the thickness of the removed NiFeCo (or CoFe) surface layer if the backsputter time is longer than 3 s. However, it is found that the giant magnetoresistance (GMR) value decreases with an increase of backsputter time, which is probably due to interface disruption during backsputter. It is found that 3–5 s backsputter can produce GMR values as high as in situ CrPtMn-pinned spin valves. The GMR value is around 8% for ex situ CrPtMn-pinned spin valves with a configuration of Ta(30 Å)/NiFe(45 Å)/CoFe(10 Å)/Cu(30 Å)/CoFe(41 Å)/CrPtMn(300 Å). © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357145
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Fabrication and properties of spin dependent tunneling junctions with CoFeHfO as free layers (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6754-6756 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Spin-dependent tunneling (SDT) structures of Ta–Cu–Ta–CoFeHfO–Al2O3–FeCo–CrPtMn have been deposited by rf diode sputtering. The junctions have been fabricated using photolithographic techniques. A junction magnetoresistive ratio as high as 34% has been obtained after annealing the junctions at 250 °C for 1 h. The junctions have a typical bias voltage of 475 mV at half-maximum magnetoresistance values. The resistance–area–product is about 1 MΩ μm2, and the dc breakdown voltage is about 1.5 V. AlN has also been investigated as a barrier for the junctions. CoFeHfO layers have a high in-plane induced anisotropy field of 65 Oe and a high 4πMs value of 1.2 T, leading to a ferromagnetic resonance frequency higher than 2 GHz. This material has a high bulk resistivity of 1000 μΩ cm, resulting in a small eddy current effect. Therefore, a SDT device with CoFeHfO as the free layer is an attractive candidate for high-speed applications. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357833
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Micromagnetic design of spin dependent tunnel junctions for optimized sensing performance (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 4679-4681 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Pinned spin dependent tunneling devices have been fabricated into high sensitivity magnetic field sensors with many favorable properties including high sensitivity (∼10 μOe/Hz at 1 Hz and ∼100 nOe/Hz at 〉10 kHz), a linear bipolar output versus applied field, high processing yields, and high temperature stability and operability (over 200 °C). However, the performance of fabricated sensors has not yet approached the theoretical limit one calculates assuming ideal behavior of the sensors' ferromagnetic layers' magnetizations. Given a total magnetoresistive signal of 30%, and typical anisotropy fields and hard axis biasing conditions, there should be a region of linear nonhysteretic response at zero field with a slope of greater than 20%/Oe. Measured responses are 1%–3%/Oe, and exhibit some hysteresis. These less than desirable effects are the result of several factors including: (1) Self-demagnetizing fields of the soft (sensing) layer; (2) stray fields from the hard (pinned) layer; (3) imperfect pinning of the hard layer; and (4) interlayer magnetic coupling across the tunnel barrier. This paper describes, in detail, the extent to which these factors affect sensor performance, and specific steps to be taken in order to minimize their deleterious influence. Specifically, the simple pinned layer is replaced by an exchange coupled synthetic antiferromagnet (CoFe/Ru/CoFe), the soft layer is made to be significantly larger in the plane than the pinned layer, and the soft layer is made as thin as possible. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373128
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Thickness dependence of the anisotropic magnetoresistance in epitaxial iron films : 37th Annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 6393-6395 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The anisotropic magnetoresistance (AMR) has been measured at room temperature on a series of epitaxial iron films of various thicknesses. Seven of the films range in thickness from 5 to 20 nm, and one is 500 nm thick. The resistivity of the films was measured with current along photolithographically defined paths parallel to three directions of high symmetry in the single crystal films ([001], [110], and [111]). It was determined that the magnitude of the AMR depends upon the direction the current is applied and that this directional dependence increases with film thickness until saturating near 20 nm. The AMR is roughly 0.15% for all crystal directions in the thinnest films, while in the thickest film, the AMR is 0.08% with current along the [001] direction, 0.35% along the [110] direction, and 0.51% along the [111] direction. These values are to be compared with the AMR of bulk polycrystalline iron which is 0.2%; a weighted average over the different crystallographic directions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Picotesla field sensor design using spin-dependent tunneling devices : The 7th joint MMM-intermag conference on magnetism and magnetic materials (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 6688-6690 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Pinned spin-dependent tunneling devices were fabricated and tested in a mode suited for low-field sensing. The basic structure of the devices was NiFeCo125/Al2O325/CoFe70/Ru9/CoFe70/ FeMn125 (in Å). This structure had a tunneling resistivity of 110 MΩ μm2 and exhibited a 20% magnetoresistance when a field was swept along the easy direction of the soft electrode. High sensitivity, low hysteresis operation was achieved by applying a bias field orthogonal to the easy axis. A sensitivity of 3%/Oe with negligible hysteresis was observed using this mode of operation. A sensor using this type of material was designed to achieve a minimum resolvable field in the picotesla range. The sensor consists of a bridge with four elements, each having 16 tunnel junctions in series. A signal-to-noise ratio of 1:1 at 1 pT (10−8 Oe) is possible assuming achievable values for the tunneling resistivity, device size, bias level, and sensitivity. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367861
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...