The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle dia...

Evaporation-induced self-assemblies (EISAs) with various morphologies were selectively fabricated by drying a solution containing polypyrrole nanoparticles. The morphogenesis of EISAs was strongly dependent upon the solvent evaporation rate and the nanoparticle concentration. In the case of fast evaporation, 2-D dendrites or pseudo 1-D dendrites were observed. When the liquid medium evaporated ...

Magnetic nanoparticles smaller than ~15 nm in diameter and with high magnetocrystalline anisotropies K1 ≥ 1 MJ m can be used as building blocks for next-generation permanent magnets. Advances in processing steps are discussed, such as self-assembly, alignment of the easy axes and appropriate nanostructuring that will enable the fabrication of densely packed nanoparticle assemblies with improved...

The characterization of protein-nanoparticle assemblies in solution remains a challenge. We demonstrate a technique based on a graphene microelectrode for structural-functional analysis of model systems composed of nanoparticles enclosed in open-pore and closed-pore ferritin molecules. The method readily resolves the difference in accessibility of the enclosed nanoparticle for charge transfer a...

The characterization of protein-nanoparticle assemblies in solution remains a challenge. We demonstrate a technique based on a graphene microelectrode for structural-functional analysis of model systems composed of nanoparticles enclosed in open-pore and closed-pore ferritin molecules. The method readily resolves the difference in accessibility of the enclosed nanoparticle for charge transfer a...

High anisotropy, L1 0 , FePt nanoparticle assemblies consisting of 4 nm diameter particles are considered a potential data storage medium beyond 1 Tbit/in 2. However, annealing at temperatures >500°C is required to form the high anisotropy phase. Recently work on the evolution of FePt nanoparticle assemblies as a function of annealing temperature has shown that for T anneal > 650°C a substantia...

In this work we give a detailed account of the use of small angle neutron scattering to study the properties of polymer mediated, self assembled nanoparticle arrays as a function of annealing temperature. The results from neutron scattering are compared with those obtained from x-ray diffraction. Both techniques show that particle size increases with annealing temperatures of 580°C and above. T...

Near-field plasmonic coupling and local field enhancement in metal nanoarchitectures, such as arrangements of nanoparticle clusters, have application in many technologies from medical diagnostics, solar cells, to sensors. Although nanoparticle-based cluster assemblies have exhibited signal enhancements in surface-enhanced Raman scattering (SERS) sensors, it is challenging to achieve high reprod...

Nanoparticle assemblies can be investigated in 3 dimensions using electron tomography. However, it is not straightforward to obtain quantitative information such as the number of particles or their relative position. This becomes particularly difficult when the number of particles increases. We propose a novel approach in which prior information on the shape of the individual particles is explo...

Nanoparticle assemblies have attracted enormous scientific interest during the last years, due to their unique properties compared to those of their building blocks. To understand the origin of these properties and to establish the connection with their structure, a detailed and quantitative structural characterization is essential. Transmission electron microscopy has been widely used to inves...