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

A bi-component nanostructured system composed by a Co dot array embedded in a NiFe antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique. Reference samples constituted by the sole Co dots or NiFe 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 NiFe 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.