Effect of flattened surface morphology of anodized aluminum oxide templates on the magnetic properties of nanoporous Co/Pt and Co/Pd thin multilayered films

Nguyen, Tu N.; Fedotova, Julia; Kasiuk, J.; Bayev, V.; Купреева, О. В.; Lazarouk, S. K.; Manh, Do Hung; Vu, Dinh Lam; Chung, Sunjae; Åkerman, Johan; Altynov, V. A.; Maximenko, Alexey

doi:10.1016/j.apsusc.2017.08.238

Cited by 27 publications

(16 citation statements)

References 36 publications

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“…By increasing the antidot hole diameter, the in-plane coercivity increment reaches the maximum for S3 antidot arrays samples, in concordance with the results obtained from MOKE measurements (see figure 3 OOP magnetic anisotropy for Co/Py bilayer antidot samples can be ascribed to a strong interfacial exchange coupling between the two FM materials. In fact, antidot thin films deposited on the top-surface of nanoporous alumina membrane templates reproduce the intrinsic surface roughness of the patterned templates [26,27] and develop a crescent shape during the thin film deposition process, as indicated at figure 2(h) and reported in ref. [6,21,23].…”

Section: Resultssupporting

confidence: 71%

Enhancement the perpendicular magnetic anisotropy of nanopatterned hard/soft bilayer magnetic antidot arrays for spintronic application

et al. 2020

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Development of perpendicular magnetic anisotropy (PMA) thin films is a requisite for many applications. In this work, we have illustrated the enhancement of the PMA of Hard (Co)/ Soft (Permalloy, Py) ferromagnetic bilayers by depositing them onto nanoporous anodic alumina membranes with different hole diameters varying in the range between 30 nm and 95 nm. A dramatic change in the hysteresis loops behaviour with hole size, D, and magnetic surface cover ratio parameters has been observed: (1) for samples with small antidot hole diameters, the in-plane (INP) hysteresis loops show single-step magnetic behaviour; (2) for D = 75 nm, the hysteresis loops of Co/Py and Py samples exhibit a multistep magnetic behaviour; (3) a decreasing coercivity in the INP hysteresis loops for antidot arrays samples with D > 75 nm has been detected as a consequence of the reduction of the in-plane magnetic anisotropy and the rising of the out-of-plane component. A crossover of magnetic anisotropy from the in-plane to out-of-plane for bilayer antidot samples has been observed for Co/Py ferromagnetic bilayers, favoured by the interfacial exchange coupling between the two ferromagnetic materials. These findings can be of high interest for the development of novel magnetic sensors and for perpendicular-magnetic recording patterned media based on template-assisted deposition techniques.

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Section: Resultssupporting

confidence: 71%

Enhancement the perpendicular magnetic anisotropy of nanopatterned hard/soft bilayer magnetic antidot arrays for spintronic application

et al. 2020

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“…It seems that an increased OOP magnetization distribution was obtained for this sample with a 75 nm hole diameter related to the underlying surface morphology of the patterned substrate of the NPAAM. In fact, antidot (AD) thin films deposited on the top-surface of NPAAM templates reproduce the intrinsic surface roughness of the patterned templates, − but they also develop a crescent shape during the thin film deposition process, as sketched in Figure c. − These two morphological features can determine the magnetic anisotropy of the material. Thus, the magnetic moments between nanoholes remain aligned parallel within the film plane, while magnetic moments along the walls of the nanoholes are perpendicularly aligned to the film plane, as schematically shown in Figure c.…”

Section: Resultsmentioning

confidence: 99%

Tuning Nanohole Sizes in Ni Hexagonal Antidot Arrays: Large Perpendicular Magnetic Anisotropy for Spintronic Applications

Salaheldeen

Méndez

Vega

et al. 2019

ACS Appl. Nano Mater.

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Perpendicular magnetic anisotropy (PMA) in transition metal thin films offers a pathway for enabling the interesting physics of nanomagnetism and developing a wide range of spintronics applications. We demonstrate a simple method to obtain Ni thin films with PMA by depositing them onto nanoporous anodic alumina membranes (NPAAMs), with different pore diameters varying in the range between 32 ± 2 and 93 ± 1 nm. Thus, several sets of Ni antidot arrays thin films have been fabricated with different hole diameters, 35 nm ≤ d ≤ 89 nm, and fixed interhole distances, D int , around 103 ± 2 nm but reducing the edge-to-edge separation between adjacent antidots, (W = D int − d), and in two different situations, by considering that W is well above or below the layer thickness, t, of the thin film. The crossover from the in-plane magnetization to out of plane magnetization in a ferromagnetic thin film has been achieved by modifying only the nanopore size of the patterned anodic alumina template and the experimental results were supported by micromagnetic simulations performed with Mumax 3 code. A dramatic change in the coercivity, H C , dependence with d and W parameters has been observed with a critical nanohole diameter, d c , at which the appearance of the perpendicular magnetization is observed. The decreasing of the inplane coercivity for samples with d > 75 nm is due to the weakened of the in-plane magnetic anisotropy and the rising of the out of plane component. The effective perpendicular magnetic anisotropy energy density for Ni antidot thin film with d = 90 nm and t = 20 nm is around 1.44 erg/cm 2 , larger than that obtained by traditional approaches for Ni films with PMA (0.03−0.2 erg/cm 2 ). These findings point toward antidot thin films as novel routes to engineer the magnetic behavior of ferromagnetic metal with large PMA, which might entail a milestone for future applications in bit patterned magneto-optic perpendicular recording media and spintronic devices.

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“…Magnetic anti-dot arrays have been developed, typically taking advantage of the occurrence of pinning of the domain walls at the edges of the holes, which hinders domain wall motion. In this fashion, complete magnetization in the direction of the applied field (magnetic saturation) will take place at higher magnetic fields compared to the case of continuous films 63,64,[289][290][291] . Further control over the magnetic behavior was achieved by the engineering of the diameter of the holes and the edge to edge distance between holes by tailoring the alumina template (w) [292][293][294] .…”

Section: Template Assisted Fabrication Of Inorganic Structuresmentioning

confidence: 98%

Revisiting anodic alumina templates: from fabrication to applications

2021

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Effect of flattened surface morphology of anodized aluminum oxide templates on the magnetic properties of nanoporous Co/Pt and Co/Pd thin multilayered films

Cited by 27 publications

References 36 publications

Enhancement the perpendicular magnetic anisotropy of nanopatterned hard/soft bilayer magnetic antidot arrays for spintronic application

Enhancement the perpendicular magnetic anisotropy of nanopatterned hard/soft bilayer magnetic antidot arrays for spintronic application

Tuning Nanohole Sizes in Ni Hexagonal Antidot Arrays: Large Perpendicular Magnetic Anisotropy for Spintronic Applications

Revisiting anodic alumina templates: from fabrication to applications

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