Large magnetoresistance in Heusler alloy-based current perpendicular to plane giant magnetoresistance sensors

TY - JOUR

T1 - Large magnetoresistance in Heusler alloy-based current perpendicular to plane giant magnetoresistance sensors

AU - Saenphum, N.

AU - Chureemart, J.

AU - Evans, R. F.L.

AU - Chantrell, R. W.

AU - Chureemart, P.

N1 - © 2021 IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2021/7/19

Y1 - 2021/7/19

N2 - Increasing the data storage in next-generation hard disk drives requires a reduction in the physical dimensions of read sensors. Tunneling magnetoresistance heads yield high magnetoresistance (MR) ratio but with a high resistance-area product (RA) that is suboptimal for devices. Giant magnetoresistance (GMR) head using different materials is an alternative way to improve reader performance with high MR ratio and low RA. In this paper, we theoretically study the effect of material properties and the layer thickness on RA and MR ratio in a trilayer system via an atomistic model combined with the spin transport model. The GMR stack can be constructed by the atomistic model and the RA and MR ratio can be directly calculated by considering the spin accumulation and spin current from the spin transport model. It is found that the spin valve using the (Figure presented) Heusler alloy electrode with high spin polarization exhibits a high MR ratio and RA of 64 (Figure presented) which is better than the spin valves using conventional ferromagnets such as Co, NiFe and CoFe. Moreover, we consider the thickness dependence of the change of RA ((Figure presented)). Increasing the free layer thickness yields the increase in (Figure presented) and MR ratio because of the enhancement of the bulk spin scattering. Additionally, the results show that the (Figure presented) depends on the spin diffusion length of the nonmagnetic materials ((Figure presented)). The (Figure presented) increases from 3 up to 10 (Figure presented) when (Figure presented) increases from 35 to 1200 nm. This investigation shows the possibility for read head design of HDDs with areal density beyond 2 Tb in-2.

AB - Increasing the data storage in next-generation hard disk drives requires a reduction in the physical dimensions of read sensors. Tunneling magnetoresistance heads yield high magnetoresistance (MR) ratio but with a high resistance-area product (RA) that is suboptimal for devices. Giant magnetoresistance (GMR) head using different materials is an alternative way to improve reader performance with high MR ratio and low RA. In this paper, we theoretically study the effect of material properties and the layer thickness on RA and MR ratio in a trilayer system via an atomistic model combined with the spin transport model. The GMR stack can be constructed by the atomistic model and the RA and MR ratio can be directly calculated by considering the spin accumulation and spin current from the spin transport model. It is found that the spin valve using the (Figure presented) Heusler alloy electrode with high spin polarization exhibits a high MR ratio and RA of 64 (Figure presented) which is better than the spin valves using conventional ferromagnets such as Co, NiFe and CoFe. Moreover, we consider the thickness dependence of the change of RA ((Figure presented)). Increasing the free layer thickness yields the increase in (Figure presented) and MR ratio because of the enhancement of the bulk spin scattering. Additionally, the results show that the (Figure presented) depends on the spin diffusion length of the nonmagnetic materials ((Figure presented)). The (Figure presented) increases from 3 up to 10 (Figure presented) when (Figure presented) increases from 35 to 1200 nm. This investigation shows the possibility for read head design of HDDs with areal density beyond 2 Tb in-2.

KW - atomistic model

KW - Heusler alloy-based CPP-GMR sensors

KW - spin accumulation model

UR - http://www.scopus.com/inward/record.url?scp=85111235129&partnerID=8YFLogxK

U2 - 10.1088/1361-6463/ac0ca4

DO - 10.1088/1361-6463/ac0ca4

M3 - Article

AN - SCOPUS:85111235129

SN - 0022-3727

VL - 54

JO - Journal of Physics D: Applied Physics

JF - Journal of Physics D: Applied Physics

IS - 39

M1 - 395004

ER -