Daniela Sudfeld

SPECS Surface Nano Analysis GmbH | SPECS · Business Development

For researchers in metallurgy, energy storage or functional nanomaterials, where elemental distribution is crucial to performance, full characterization is more difficult by decreasing feature sizes and increasingly complex architectures. Two-dimensional imaging and analytical techniques often cannot characterize nanostructures completely. A new th...

Zinc oxide nanocrystals are synthesized using the chemical vapor synthesis (CVS) technique. Diethylzinc is used as zinc precursor. Synthesized zinc oxide nanocrystals are characterized by X-ray diffraction (XRD), nitrogen adsorption and desorption, transmission electron microscopy (TEM) and dynamic laser scattering. As-synthesized zinc oxide has a...

Mass-filtered Fe and FeCo nanoparticles are deposited under soft-landing and ultra-high vacuum conditions on the bare W(110) surface. The structure and the stoichiometry of FeCo alloy nanoparticles are determined by ex situ high resolution transmission electron microscopy (HRTEM) and energy-dispersive x-ray spectroscopy (EDX) on single nanoparticle...

Thin silicon films are of great importance for large-area electronic applications, for example, as the basis for switching electronics in flat-panel display devices or as the active layer of solar cells. In this paper, we show that silicon nanoparticles have the potential to be used as raw material for further processing toward a microcrystalline s...

The lattice vibrational dynamics of supported, self-assembled, isolated 57Fe nanoclusters was studied by nuclear resonant inelastic x-ray scattering and molecular dynamics calculations. The morphological and struc-tural properties and the chemical state of the experimental nanoclusters were investigated by atomic force microscopy, high resolution t...

GaAs nanowhiskers were grown by metal-organic vapor-phase epitaxy on (111)B GaAs substrates. The diameter of the nanowhiskers was defined by monodisperse Fe nanoparticles deposited on the GaAs substrate from the vapor phase. The growth temperature of the whiskers was investigated from 480 to 520 ° C . The whiskers are preferentially directed along...

GaAs/InxGa1-xAs/GaAs hetero structures nanowires were grown by metal-organic vapor-phase epitaxy on (I I I)B GaAs substrate using the vapor-liquid-solid growth mode. The diameter of the nanowires was defined by monodisperse gold nanoparticles deposited on the GaAs substrate. High-resolution electron transmission microscopy investigation revealed th...

GaAs/In x Ga 1Àx As/GaAs heterostructures nanowires were grown by metal-organic vapor-phase epitaxy on (1 1 1)B GaAs substrate using the vapor–liquid–solid growth mode. The diameter of the nanowires was defined by monodisperse gold nanoparticles deposited on the GaAs substrate. High-resolution electron transmission microscopy investigation revealed...

FePt nanoparticles are promising materials for high-density magnetic data storage media [1] and bio-medical applications such as drug-targeting and hyperthermia [2]. To understand their magnetic properties [3] it is essential to get insights into the lattice structure of isolated nanoparticles which influence the magnetic behavior. Typically, latti...

TiC-supported size- and shape-selected Au nanoparticles with well defined interparticle distances were synthesized by diblock copolymer encapsulation. Atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD) have been used to investigate the correlation...

InGaAs nanowhiskers were grown by metal-organic vapor-phase epitaxy on (111)B GaAs substrates using the vapor-liquid-solid growth mode. The diameter of nanowhiskers was defined by monodisperse gold nanoparticles deposited on the GaAs substrate from the liquid phase. By adjusting the triethylgallium to trimethylindium flow ratio, InxGa1−xAs whiskers...

X-ray absorption and magnetic circular dichroism spectra at both the Fe and Pt L-3,L-2 edges were measured on wet-chemically synthesized monodisperse Fe50Pt50 particles with a mean diameter of 6.3 nm before and after complete removal of the organic ligands and the oxide shell covering the particles by soft hydrogen plasma resulting in a pure metall...

Single crystal In x Ga1−x As nanowhisker were grown by metal-organic vapour-phase epitaxy on (111)B GaAs substrates using the vapour–liquid–solid growth mode. Present study is aimed to the direct evaluation of the lattice parameter, the phase, and the composition of nanowhiskers with high spatial resolution by high-resolution transmission electron...

Calculated magnetophoretic mobility of a variety of magnetic compounds has identified FeCo to be an alternative for magnetite in in vitro biological cell separations. The synthesis of FeCo nanoparticles and the resulting microstructure is discussed as a function of the particle size. Their synthesis kinetics is modeled using a consecutive decomposi...

Analytical transmission electron microscopy is a proper method so as to uncover microstructure and composition of novel magnetic nanocrystals potentially used as biological markers. The focus of this study is the preparation and characterization of the (Fe1-xCox)(1-y)Pt-y alloyed nanoparticles utilizing high-resolution transmission electron microsc...

The zero field cooled (ZFC) and field cooled (FC) low-field magnetic moment m of a dense frozen ferrofluid containing Fe55Co45 particles of size 4.6nm in hexane exhibits irreversibility at temperatures T < T b≈ 30 K. FC in μ 0 H ≤ 1 T gives rise to shifted minor hysteresis loops below T b. At T c≈ 10 K, sharp peaks of m ZFC and of the ac susceptibi...

The best way to achieve a virgin state of a magnetized sample is to heat it up to a temperature high enough to destroy every magnetic order and thereafter cooling it down in a zero magnetic field. This procedure is often not possible because high temperatures may cause irreversible changes in the sample's constitution e. g. by crystallization in am...

Magnetoresistive biosensors use a new detection method for molecular recognition reactions based on two recently developed techniques and devices: Magnetic markers and XMR sensors, where XMR means either giant magnetoresistance (GMR) or tunneling magnetoresistance (TMR). The markers are specifically attached to the target molecules, and their magne...

Calculated magnetophoretic mobility of a variety of magnetic compounds has identified FeCo to be an alternative for magnetite and maghemite in vitro biological cell separations. The synthesis of FeCo nanoparticles and the resulting microstructure is discussed as a function of the particle size. Their synthesis kinetics is modeled using a consecutiv...

Paramagnetic carriers, which are linked to antibodies enable highly specific biological cell separations. With the colloidal synthesis of superparamagnetic Co and FeCo nanocrystals with superior magnetic moments the question about their potential to replace magnetite as the magnetically responsive component of magnetic beads is addressed. Starting...

Analysis of Monodispersed FeCo Alloyed Nanoparticles by High-Resolution Transmission Electron Microscopy - Volume 9 Issue S03 - Daniela Sudfeld, Inga Ennen, Wiebke Hachmann, Klaus Wojczykowski, Peter Jutzi, Günter Reiss, Andreas Hütten

Our study presents experimental results on Co2MnSi thin-film preparation and resulting magnetic properties of the Co2MnSi Heusler alloy. The focus of our work is on the important role of the microstructure and the magnetic properties relationships of Co2MnSi thin films prepared using dc magnetron sputtering. We examined the microstructure evolution...

Recognizing the technological potential of magnetic nanocrystals for the next generation of high density data storage [S. Sun and C. B. Murray, J. Appl. Phys. 85, 4325 (1999)] and as markers in biological systems for detection and manipulation of attached molecules, [L. Lagae, R. Wirix-Speetjens, J. Das, D. Graham, H. Ferreira, P. P. F. Freitas, G....

The microstructural influence of binary melt-spun AuCo and pseudo-binary AlNiCo5 permanent magnets in the optimum magnetic state on the giant magnetoresistance (GMR) have been compared to identify the origin of the magnetotransport in these metal/metal granular systems. In general, their high field GMR dependence is originated from small ferromagne...

Co nanocrystals have been prepared via two different chemical preparation routes. Microstructural characterization has been carried out by conventional and high-resolution transmission electron microscopy. Magnetic characterization reveals that Co nanocrystals with mean particle size distributions about 6 nm are ferromagnetic at room temperature. S...