Bi-Component Nanostructured Arrays of Co Dots Embedded in Ni80Fe20 Antidot Matrix: Synthesis by Self-Assembling of Polystyrene Nanospheres and Magnetic Properties.

Marco Coïsson,Federica Celegato,Paola Tiberto,Gianluca Conta,Alessandro Magni,Gabriele Barrera

doi:10.3390/nano7090232

Abstract

A bi-component nanostructured system composed by a Co dot array embedded in a Ni80Fe20 antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique. Reference samples constituted by the sole Co dots or Ni80Fe20 antidots have also been prepared, in order to compare their properties with those of the bi-component material. The coupling between the two ferromagnetic elements has been studied by means of magnetic and magneto-transport measurements. The Ni80Fe20 matrix turned out to affect the vortex nucleation field of the Co dots, which in turn modifies the magneto-resistance behaviour of the system and its spinwave properties.

Highlights

Composite magnetic materials have been the subject of intensive research both for fundamental investigations and applied research
A bi-component nanostructured system composed by a Co dot array embedded in a Ni80Fe20 antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique
Two-dimensional bi-component nanostructured (BN) arrays, constituted by Co dots embedded in a Ni80Fe20 antidot matrix (Co/Ni80Fe20), are synthesized by the self-assembling of polystyrene nanospheres (PN)

Summary

Introduction

Composite magnetic materials have been the subject of intensive research both for fundamental investigations and applied research. Depending on the chosen composition and shape (i.e., layer or nanoparticle), exchange coupling among different magnetic phases occurs and gives rise to different effects Among these emerged long-range magnetostatic interactions [14] are exchange bias [15,16], or interface interactions [17,18,19]. The possibility to tune lattice geometry of patterning (i.e., honeycomb, rhomboid) gave rise to magnetoresistance response strongly dependent on lattice geometry [27] In this context, self-assembling lithography techniques [28,29,30,31] have proven their viability for obtaining low-cost, large-area nanopatterned magnetic systems with interesting magnetic and magneto-transport properties. The preparation technique and investigation methods discussed in this paper can be exploited to pick suitable magnetic materials to be coupled, and to optimise the dots size and their centre-to-centre distance in order to reach the desired effect

Experimental

Results and Discussion

Conclusions