HDD Reader Technology Roadmap to an Areal Density of 4 Tbpsi and Beyond

Albuquerque, G.; Hernández, Stephanie; Kief, M. T.; Mauri, D.; Lei, Wang

doi:10.1109/tmag.2021.3081042

Cited by 14 publications

(10 citation statements)

References 48 publications

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“…Subsequently, the MR ratio of both systems can be evaluated. Importantly, the reader stack with the SAF layer provides a high RA of 30.22 mΩ•µm 2 and enhances the MR ratio up to 73.24% at 0 K, which is in excellent agreement with previous experiments [40,41], whereas the reader stack without the SAF layer gives a lower RA of 16.75 mΩ • µm 2 and a low MR ratio of 16.79%. This may be explained by the fact that the number of interfaces has a significant impact on the RA and MR ratio values, which are strongly contingent on both bulk and interfacial spin scatterings.…”

Section: Resultssupporting

confidence: 91%

“…The write head, read head, and recording medium are the main components, playing a prominent role in the improvement of HDD performance. Shrinking the size of the data bits is a promising way to achieve a high areal density (AD) beyond 2 Tb in −2 in HDDs [1][2][3][4][5]. A scaling down of all components in the devices is necessary, and in particular, * Author to whom any correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

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Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Khamtawi,

Saenphum,

Chantrell

et al. 2023

J. Phys. D: Appl. Phys.

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Heusler alloy has been widely utilized in magnetoresistive sensors to enhance the device performance. In this work, we theoretically investigate the performance of Heusler-alloy-based magnetoresistive sensors with a synthetic antiferromagnet (SAF) layer. The atomistic model combined with the spin accumulation model will be used in this work. The former is used to construct the reader stack and investigate the magnetization dynamics in the system. The latter is employed to describe the spin transport behavior at any position of the structure. We first perform simulations of the exchange bias (EB) phenomenon in the IrMn/ C o 2 F e S i (CFS) system providing a high EB field. Then, a realistic reader stack of IrMn/CFS/Ru/CFS/Ag/CFS is constructed via an atomistic model. Subsequently, the resistance–area product (RA) and magnetoresistance (MR) ratio of the reader can be calculated by using the spin accumulation model. As a result of the spin transport behavior in the Heusler-alloy-based reader stack including SAF structure at 0 K, an enhancement of the MR ratio up to 120 % and RA < 40 m Ω ⋅ μ m 2 can be observed. This study demonstrates the important role of the Heusler alloy and SAF layer in the development of magnetoresistive sensors for the application of readers in hard disk drives with an areal density beyond 2 Tb in−2.

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Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Khamtawi,

Saenphum,

Chantrell

et al. 2023

J. Phys. D: Appl. Phys.

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“…This requires the reader technology to have superior reading resolution and SNR. 65,66 Therefore, new reader technologies must be developed.…”

Section: Magnetic Recording and Requirements For Reader Technologymentioning

confidence: 99%

Perspective on nanoscale magnetic sensors using giant anomalous Hall effect in topological magnetic materials for read head application in magnetic recording

Nakatani,

Kulkarni,

Suto

et al. 2024

Applied Physics Letters

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Recent advances in the study of materials with topological electronic band structures have revealed magnetic materials exhibiting giant anomalous Hall effects (AHEs). The giant AHE has not only attracted the research interest in its mechanism but also opened up the possibility of practical application in magnetic sensors. In this article, we describe simulation-based investigations of AHE magnetic sensors for applications to read head sensors (readers) of hard disk drives. With the shrinking of magnetic recording patterns, the reader technology, which currently uses multilayer-based tunnel magnetoresistance (TMR) devices, is associated with fundamental challenges, such as insufficient spatial resolution and signal-to-noise ratio (SNR) in sensors with dimensions below 20 nm. The structure of an AHE-based device composed of a single ferromagnetic material is advantageous for magnetic sensors with nanoscale dimensions. We found that AHE readers using topological ferromagnets with giant AHE, such as Co2MnGa, can achieve a higher SNR than current TMR readers. The higher SNR originates from the large output signal of the giant AHE as well as from the reduced thermal magnetic noise, which is the dominant noise in TMR readers. We highlight a major challenge in the development of AHE readers: the reduction in the output signal due to the shunting of the bias current and the leakage of the Hall voltage through the soft magnetic shields surrounding the AHE reader. We propose reader structures that overcome this challenge. Finally, we discuss the scope for future research to realize AHE readers.

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“…Burgeoning global data consumption owing to the advancement of information, communication, and computing technologies has ensured that the demand for the continuous development of recording media from data centers continues to surge. , The hard-disk-drive (HDD) is the main storage device in any data center because it satisfies the requirements of low cost, large capacity, and nonvolatility. A promising material for high-density magnetic recording media is a nanometer-thick L 1 0 -FePt nanogranular film, , which is used in heat-assisted-magnetic-recording (HAMR) technology .…”

mentioning

confidence: 99%

Thermal Modulation of Magnetization Dynamics in Nanometer-Thick L1₀-FePt Nanogranular and Continuous Films for High-Density Magnetic Recording Media

Sasaki

Suzuki

Mandal

et al. 2023

ACS Appl. Nano Mater.

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Thermal modulation of magnetism in magnetic recording media is a novel technique to increase the recording density. L10-FePt is a promising material for the media; however, experimental observation of its magnetization dynamics characterized by the Gilbert damping constant α is technically difficult because the dynamics is in the terahertz (THz) frequency range. A cutting edge technique in THz spintronics, an all-optical pump–probe method, leads us to achieve the detection of THz magnetization dynamics in nanometer-scale thin films with thermal heating. Here, thermal modulation of the magnetization dynamics for L10-FePt nanogranular and continuous films is discussed using the all-optical method. The effective damping constant for the nanogranular film decreased from 0.18 to 0.064 with increasing the temperature, and the thermal modulation decreased the extrinsic contribution, while this increased α above 530 K. This observation regarding the thermal modulation of the magnetic damping is valuable to design future high-density magnetic recording media.

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HDD Reader Technology Roadmap to an Areal Density of 4 Tbpsi and Beyond

Cited by 14 publications

References 48 publications

Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Perspective on nanoscale magnetic sensors using giant anomalous Hall effect in topological magnetic materials for read head application in magnetic recording

Thermal Modulation of Magnetization Dynamics in Nanometer-Thick L1₀-FePt Nanogranular and Continuous Films for High-Density Magnetic Recording Media

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HDD Reader Technology Roadmap to an Areal Density of 4 Tbpsi and Beyond

Cited by 14 publications

References 48 publications

Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet

Perspective on nanoscale magnetic sensors using giant anomalous Hall effect in topological magnetic materials for read head application in magnetic recording

Thermal Modulation of Magnetization Dynamics in Nanometer-Thick L10-FePt Nanogranular and Continuous Films for High-Density Magnetic Recording Media

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Product

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About

Thermal Modulation of Magnetization Dynamics in Nanometer-Thick L1₀-FePt Nanogranular and Continuous Films for High-Density Magnetic Recording Media