ABSTRACT
The P03 beamline, also called the microfocus and nanofocus X-ray scattering (MiNaXS) beamline, exploits the excellent photon beam properties of the low-emittance source PETRA III to provide a microfocused/nanofocused beam with ultra-high intensity for time-resolved X-ray scattering experiments. The beamline has been designed to perform X-ray scattering in both transmission and reflection geometries. The microfocus endstation started user operation in May 2011. An overview of the beamline status and of some representative results highlighting the performance of the microfocus endstation at MiNaXS are given.
ABSTRACT
The installation of large scale colloidal nanoparticle thin films is of great interest in sensor technology or data storage. Often, such devices are operated at elevated temperatures. In the present study, we investigate the effect of heat treatment on the structure of colloidal thin films of polystyrene (PS) nanoparticles in situ by using the combination of grazing incidence small-angle X-ray scattering (GISAXS) and optical ellipsometry. In addition, the samples are investigated with optical microscopy, atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). To install large scale coatings on silicon wafers, spin-coating of colloidal pure PS nanoparticles and carboxylated PS nanoparticles is used. Our results indicate that thermal annealing in the vicinity of the glass transition temperature T(g) of pure PS leads to a rapid loss in the ordering of the nanoparticles in spin-coated films. For carboxylated particles, this loss of order is shifted to a higher temperature, which can be useful for applications at elevated temperatures. Our model assumes a softening of the boundaries between the individual colloidal spheres, leading to strong changes in the nanostructure morphology. While the nanostructure changes drastically, the macroscopic morphology remains unaffected by annealing near T(g).
Subject(s)
Membranes, Artificial , Nanoparticles/chemistry , Polystyrenes/chemistry , Temperature , Colloids/chemistry , Particle Size , Surface PropertiesABSTRACT
We show a route to produce a two- and three-dimensional network of nanoparticles via polymer-mediated self-assembly. A negatively charged polymer, CO2-functionalized poly (para-phenyleneethylene) (PPE-CO2), is used to build this network of iron-platinum (Fe-Pt) nanoparticles. The nanoparticles arrange locally in hexagonal and cubic lattice type network structures. The size and form of the networks are characterized with atomic force microscopy (AFM), transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and grazing incidence small-angle X-ray scattering (GISAXS). In thin film the network is perturbed due to the force field acting during spin coating.
ABSTRACT
Cobalt (Co) sputter deposition onto a colloidal polymer template is investigated using grazing incidence small-angle X-ray scattering (GISAXS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). SEM and AFM data picture the sample topography, GISAXS the surface and near-surface film structure. A two-phase model is proposed to describe the time evolution of the Co growth. The presence of the colloidal template results in the correlated deposition of an ultrathin Co film on the sample surface and thus in the creation of Co capped polystyrene (PS) colloids. Well below the percolation threshold, the radial growth is restricted and only height growth is observed.
