Functionality by Artificial Property Contrasts on the Nanoscale

Based on our previous work, the project will continue focusing on electronic properties of metallic nanostructures, which promise to effect their functionality. For this purpose, nanostructures are prepared exploiting the selforganization of micelles or colloids. In this way, arrays of nanoparticles are obtained offering a direct contrast of properties on the nanoscale. Alternatively, such arrays can be used as etching marks for transfering their pattern into the supporting substrate, thus leading to an indirect property contrast. Besides preparational aspects, emphasis will be put on the functional behavior of ensembles of nanostructures like particles, pillars or pores. Additionally to ur previous work, the role of electron spin for excitations and transport will be studied.

For single nanostructures like nanoparticles focus will be on the Locad Density Of States (LDOS) as determined by Scanning Tunneling Spectroscopy (STS) at 5 K. This opens the perspective to additionally study tunneling-induced local temperature effect or even inelastic processes besides the expected size-dependence of the LDOS. The STS measurements will be complemented by electron spectroscopies like XPS or XAS performed at he synchrotron BESSYII. This part of the project will focus on Mn, Pt, Pd, In nanoparticles.

To obtain a specific functionality in case of particle ensembles, nm-magnetic arrays of (unlaw)-blocked nanoparticles like Au/Al2O3/Nb will be analyzed and combined with an ITO-electrode. Especially, the rectifying properties of such arrangements will be studied when exposing them to light of various wave lengths.