Magnetic Properties of Co/Cu/Py Antidot Films With Different Pore Diameters

Abstract

The magnetic properties of ordered nanoscale Co/Cu/Py multilayer antidot films with different pore sizes prepared on top of nanoporous alumina membranes are presented. By using Co and Py films separated by a Cu thin layer, and tuning the pore diameters of the NAMs we were able to play with the coercivity of the films and observe stepped magnetization curves, as a consequence of the different coercivities of the Co and Py films. The magnetic properties of the multilayer antidots have been measured and compared with results obtained for antidots of Cu/Py. The magnetization reversal process that occurs in each individual layer and in the multilayer was studied by means of micromagnetic simulations.* Email: joel.briones@usach.cl I. INTRODUCTIONNanostructured magnetic elements have received much attention from the scientific community in the last two decades due to their potential applications, ranging from sensors for the electronic and electromechanical industry to the storage media for the magnetic recording industry. The magnetic nanostructures usually referred as antidots are based on magnetic thin films with periodic arrays of holes. In the last years the study of magnetic nanoparticles based on arrays of antidots have attracted intensive attention because they are a promising candidates for a new generation of ultra-high-density magnetic storage media, and an exciting topic in fundamental physics . In an antidot array, magnetic features such as coercive field, anisotropy axes and reversal mechanisms, among others, can be tailored by tuning the geometric parameters of the array [1][2][3][4]. Generally, the studies have been focused in antidot systems of single layered magnetic materials ; and more recently on multilayered ones [25][26][27][28][29][30][31][32][33]. Antidots of NiFe (Py) [1,[5][6][7][8][9][10][11][12][13][14][15][16] and Ni [17,18] films are widely studied presenting an increased coercivity compared to the continuous form. Antidots made of Co present a large enhancement of the coercivity [2][3][4][19][20][21][22][23][24], and are usually deposited with Pt for out of plane recording purposes [25][26][27]. Arrays of Co/Cu/NiFe, CoFe/Cu/NiFe and [Co/Cu] N multilayered antidots have been studied previously by means of magneto-transport measurements [28][29][30]. In this work we present the magnetic properties of ordered nanoscale Co/Cu/Py antidots arrays with different pore sizes prepared on top of nanoporous alumina membranes (NAMs). By using Co and Py films separated by a Cu thin layer, and tuning the pore diameters of the NAMs we were able to play with the coercivity of the films and observe stepped magnetization curves, as a consequence of the different coercivities of the Co and Py films. By systematic measurements of the magnetic and magnetotransport properties of these samples, and comparing with simulations, we were able to understand in more detail the magnetization reversal that takes place in these multilayer antidots. II.EXPERIMENTAL PROCEDURE Nanoporous alumina membranes were prepared fr...

In situ Polarized Neutron Reflectometry: Epitaxial Thin-Film Growth of Fe on Cu(001) by dc Magnetron Sputtering

“…In addition, the detailed observation of the processes taking place during topotactic transformations [1] or the formation of self organized structures [58] can be followed up in-situ. In this context, beamlines might, however, be preferable that in addition to reflectometry also allow large-angle scattering geometries, such that additionally to the data obtained by iPNR crystal structures including defects like oxygen vacancies can be analyzed.…”