Magnetic and transport properties in ordered arrays of permalloy antidots and thin films

Abstract

The magnetotransport behaviors of two types of permalloy nanostructures, thin films and antidots, are presented and discussed. Antidots samples were prepared by sputtering a Ni 80 Fe 20 layer on top of a nanoporous alumina membrane. A counterpart continuous thin film grown on a continuous Si substrate was also prepared. The magnetoresistance ͑MR͒ was measured both as a function of the external applied magnetic field and of the angular orientation, and thus compared with the magnetization curves. The introduction of antidots is found to reduce the anisotropic MR and the angular dependence of the MR, simultaneously increasing the coercive field of the samples. The influence of the sample geometry on the perpendicular MR behavior is reported and discussed.

Correlations among magnetic, electrical and magneto-transport properties of NiFe nanohole arrays

“…We would also like to remark that for t = 100 nm, two bumps appear close to H = 0 (figures 5(e) and (f)). Similar features were observed in the out-of-plane MR curves [41], confirming the presence of a local out-of-plane magnetization component, probably resulting from material deposited around the entrance of the nanoholes, or from the pronounced AAO topography mimicked by the film.…”

Tailoring the physical properties of thin nanohole arrays grown on flat anodic aluminum oxide templates

“…The average electric current path was set parallel to the induced EA. have major repercussions on the NhA morphology, since the film deposited on top will conform to the particular surface topography of the AAO in addition to the desired mimicking of the nanopore lattice (figure 2(b)) [11,10,19]. Strikingly, an accentuated decrease of the AAO topography is visible after being subjected to ion-milling (figure 1(c)), with the hills exhibiting now an average height of ∼1-2 nm (figures 2(a) and (b)).…”

“…In fact, while Rahman et al reported a surface roughness of ∼0.4-0.5 nm for anodized sputtered Al films [16], other studies have indicated a surface roughness of ∼4 nm for non-organized AAO [17] or NhAs grown using a replica-antireplica technique [18]. One also finds several reports on NhAs with thicknesses above 10 nm grown on highly ordered AAO, where the underlying surface roughness was neglected [10,15,19,20]. In contrast, for thinner films (<10 nm), such a topography can even lead to granular thin-film morphologies [11,17].…”

Co nanostructures in ordered templates: comparative FORC analysis

“…In the particular case of the nanohole arrays, the thickness and depth of the deposited material around the upper entrance of the nanopores depend on both the deposited film thickness and the pore diameter (figure 3) [50,55]. The magnetization of this material then has an important out-of-plane (OOP) component, which influences the magnetic and magnetotransport behaviors of the Nh arrays [31,50,[55][56][57][58][59].…”