Structuration and Integration of Magnetic Nanoparticles on Surfaces and Devices

Elena Bellido, Neus Domingo, Isaac Ojea-Jiménez and Daniel Ruiz-Molina

Small, 8, 1465 - 1491, (2012)
DOI: 10.1002/smll.201101456

Abstract: Different experimental approaches used for structuration of magnetic nanoparticles on surfaces are reviewed. Nanoparticles tend to organize on surfaces through self-assembly mechanisms controlled by non-covalent interactions which are modulated by their shape, size and morphology as well as by other external parameters such as the nature of the solvent or the capping layer. Further control on the structuration can be achieved by the use of external magnetic fields or other structuring techniques, mainly lithographic or atomic force microscopy (AFM)-based techniques. Moreover, results can be improved by chemical functionalization or the use of biological templates. Chemical functionalization of the nanoparticles and/or the surface ensures a proper stability as well as control of the formation of a (sub)monolayer. On the other hand, the use of biological templates facilitates the structuration of several families of nanoparticles, which otherwise may be difficult to form, simply by establishing the experimental conditions required for the structuration of the organic capsule. All these experimental efforts are directed ultimately to the integration of magnetic nanoparticles in sensors which constitute the future generation of hybrid magnetic devices.

Structuration and Integration of Magnetic Nanoparticles on Surfaces and Devices
a) 3D AFM image of a graphene-based nanoHall sensor with cross-sections of 1 μm × 1 μm in size. b) Hall cross indicated in image (a) was functionalized with Co NPs (∼8 nm) by means of AFM-based nanolithography. c) Height profile along the white dashed line in image (b)