Magnetic antidot arrays from self-assembly template methods

Abstract

Fabrication and magnetic properties of patterned NiFeMo films electrodeposited in self-assembled nanosphere templates J. Appl. Phys. 109, 054313 (2011); 10.1063/1.3561362 Reduced saturation magnetization in cobalt antidot thin films prepared by polyethylene oxide-assisted selfassembly of polystyrene nanospheres Appl. Phys. Lett. 96, 122504 (2010); 10.1063/1.3371692Oscillatory thickness dependence of the coercive field in three-dimensional anti-dot arrays from self-assembly Using self assembly from lyotropic liquid crystalline phases and from colloidal suspensions of polystyrene spheres templates, we have prepared well-ordered, nanostructured magnetic materials. We present the results of electrochemical deposition of magnetic metals and alloys in the interstitial space between these templates. This technique has enabled us to create magnetic nanostructures with three-dimensional achitectures on length scales of 4 nm-1 m. We find changes in coercive field, by more than 1 order of magnitude, dominated by the effects of the nanoscale shapes. Varying the parameters in the preparation allows us to produce materials with predetermined magnetic parameters. The templated electrodeposition technique offers the potential of a low-cost preparation method for submicron patterned magnetic media.

Micromagnetic modeling of experimental hysteresis loops for heterogeneous electrodeposited cobalt films

“…While lithographic methods tend to be time consuming and resource intensive, 10,11 the production of evaporatively selfassembled colloidal templates is a simpler and lower-cost alternative. For example, Zhukov et al 12,13 electroplated a number of magnetic materials through evaporatively formed latex sphere arrays. They examined the dependence of H c on film thickness relative to template (sphere) diameter, emphasizing the interplay between magnetic domain wall widths and void dimensions.…”

Self-assembly Routes towards Creating Superconducting and Magnetic Arrays

“…However, in contrast to our samples, particulate materials correspond to dot, rather than anti-dot, structures. We found the value of the diameter corresponding to maximum coercivity, d max to agree with the condition d max /2 ≈ w B , where w B is the magnetic domain wall width for the material 6 .…”

“…In magnetic anti-dot samples nano-structuring significantly changes magnetization loops and value of the coercive field as we have described previously 5,6 . The coercive field, B c , shows a non-monotonic change with variation of the diameter d of spherical holes.…”

“…This technique offers new opportunities, which are not easily realized by standard lithographic methods, and allows us to create magnetic nano-structures with 3D architectures on a broad range of length scales, 20 -2000 nm. In this paper we briefly review our previous results [5][6][7][8][9][10][11][12][13] and in more detail describe some recent observations. We show that the 3D architecture of these structures produces many unique properties absent in nanostructures prepared by conventional lithographical techniques.…”

Orientation and symmetry control of inverse sphere magnetic nanoarrays by guided self-assembly

“…17,20 We have also reported initial results on guided inverse sphere arrays highlighting the significance of the shape of the guiding patterns. 21 Here, a detailed analysis for the guided self-assembly of inverse sphere magnetic monolayers is presented.…”