High resolution magnetic imaging of perpendicular magnetic recording head using frequency-modulated magnetic force microscopy with a hard magnetic tip

Lu, Wei; Li, Zhenghua; Hatakeyama, Kazutoshi; Egawa, Genta; Yoshimura, Satoru; Saito, Hitoshi

doi:10.1063/1.3378977

Cited by 19 publications

(13 citation statements)

References 12 publications

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“…Magnetic isolation of bits at 20 nm pitch (1.9 Tbit/in 2 density) is demonstrated next using a series of high-resolution MFM images in figure 4. The ability to resolve the magnetic bits at 20 nm pitch puts the resolution of our MFM capabilities at ∼10 nm half pitch, which is comparable to the best MFM resolution reported [30,31]. SEM images of the patterned bits with regular bit sizes of ∼15 nm are shown in figure 4(a).…”

supporting

confidence: 53%

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²

Yang¹,

Chen²,

Huang³

et al. 2011

Nanotechnology

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We fabricated bit-patterned media (BPM) at densities as high as 3.3 Tbit/in(2) using a process consisting of high-resolution electron-beam lithography followed directly by magnetic film deposition. By avoiding pattern transfer processes such as etching and liftoff that inherently reduce pattern fidelity, the resolution of the final pattern was kept close to that of the lithographic step. Magnetic force microscopy (MFM) showed magnetic isolation of the patterned bits at 1.9 Tbit/in(2), which was close to the resolution limit of the MFM. The method presented will enable studies on magnetic bits packed at ultra-high densities, and can be combined with other scalable patterning methods such as templated self-assembly and nanoimprint lithography for high-volume manufacturing.

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supporting

confidence: 53%

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²

Yang¹,

Chen²,

Huang³

et al. 2011

Nanotechnology

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“…The resolution is obtained from Fourier transformation of the amplitude scan line around main pole. The details of this calculation were described in reference papers 21) . The spatial resolution of amplitude imaging is 15.5 nm in this case.…”

Section: Resultsmentioning

confidence: 99%

High Coercivity and Resolution FePt•MgO-coated Tip for Imaging the Magnetic Field of Perpendicular Magnetic Write Head by Alternating Magnetic Force Microscopy (A-MFM)

Yoshimura

Yasui

et al. 2019

J. Magn. Soc. Jpn.

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High coercivity FePt•MgO films were successfully synthetized on cone-shape Si tips in a very high frequency (VHF) plasma irradiation-assisted magnetron sputtering system to prepare the MFM tips for evaluation of the AC magnetic field of perpendicular magnetic write head at high write current. Alloying with MgO significantly enhanced the coercivity of the magnetic coating due to the isolation of FePt grains by MgO. As a result, a high coercivity close to 20 kOe was achieved. The AC magnetic field images of the perpendicular magnetic write head at high write current were taken on alternating MFM (A-MFM) by this tip. A clear amplitude image with a strong signal at the main pole position was observe compared to the pure FePt layer-coated tip, which gave a blurry image and very small amplitude. Fourier analysis of the images obtained by this kind of FePt•MgO tip gives a spatial resolution of about 15 nm in air atmosphere. It is clear that the cone-shape FePt•MgO-coated MFM tip with a coercivity higher than the magnetic field to be measured is effective and capable for measuring the high AC magnetic field for an HD perpendicular magnetic write head at a very high write current.

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“…And another advantage is that a larger stray field can be generated from the magnetic nanoparticles in the AC magnetic field modulation technique, which gives higher MFM signal amplitude. The smaller minimal measurable force signal, higher signal amplitude, and better signal to noise ratio result in a better resolution in AC field-modulated MFM than the conventional one 25 .…”

Section: Discussionmentioning

confidence: 99%

Quantitatively probing the magnetic behavior of individual nanoparticles by an AC field-modulated magnetic force microscopy

Song

et al. 2016

Sci Rep

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Despite decades of advances in magnetic imaging, obtaining direct, quantitative information with nanometer scale spatial resolution remains an outstanding challenge. Current approaches, for example, Hall micromagnetometer and nitrogen-vacancy magnetometer, are limited by highly complex experimental apparatus and a dedicated sample preparation process. Here we present a new AC field-modulated magnetic force microscopy (MFM) and report the local and quantitative measurements of the magnetic information of individual magnetic nanoparticles (MNPs), which is one of the most iconic objects of nanomagnetism. This technique provides simultaneously a direct visualization of the magnetization process of the individual MNPs, with spatial resolution and magnetic sensitivity of about 4.8 nm and 1.85 × 10−20 A m2, respectively, enabling us to separately estimate the distributions of the dipolar fields and the local switching fields of individual MNPs. Moreover, we demonstrate that quantitative magnetization moment of individual MNPs can be routinely obtained using MFM signals. Therefore, it underscores the power of the AC field-modulated MFM for biological and biomedical applications of MNPs and opens up the possibility for directly and quantitatively probing the weak magnetic stray fields from nanoscale magnetic systems with superior spatial resolution.

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High resolution magnetic imaging of perpendicular magnetic recording head using frequency-modulated magnetic force microscopy with a hard magnetic tip

Cited by 19 publications

References 12 publications

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²

High Coercivity and Resolution FePt•MgO-coated Tip for Imaging the Magnetic Field of Perpendicular Magnetic Write Head by Alternating Magnetic Force Microscopy (A-MFM)

Quantitatively probing the magnetic behavior of individual nanoparticles by an AC field-modulated magnetic force microscopy

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High resolution magnetic imaging of perpendicular magnetic recording head using frequency-modulated magnetic force microscopy with a hard magnetic tip

Cited by 19 publications

References 12 publications

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in2

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in2

High Coercivity and Resolution FePt•MgO-coated Tip for Imaging the Magnetic Field of Perpendicular Magnetic Write Head by Alternating Magnetic Force Microscopy (A-MFM)

Quantitatively probing the magnetic behavior of individual nanoparticles by an AC field-modulated magnetic force microscopy

Contact Info

Product

Resources

About

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²

Fabrication and characterization of bit-patterned media beyond 1.5 Tbit/in²