Document Server@UHasselt
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Repository of the University of Hasselt containing publications in the fields of statistics, computer science, information strategies and material from the Institute for behavioural sciences.
Mostrando recursos 1 - 19 de 19
1.
Minority employees engaging with (diversity) management: An analysis of control, agency, and micro-emancipation - ZANONI, Patrizia; JANSSENS, Maddy
This study analyses how minority employees engage with control in organizations. Different from most critical studies of diversity management, which focus on how minority employees are discursively controlled, we approach (diversity) management as a constellation of both identity-regulating discourses and bureaucratic controls. We assume that minority employees are agents who actively resist and/or comply with the constellation of controls they are subject to. Based on qualitative data collected in a technical drawing company and a hospital, the specific constellation of controls in each organization is first reconstructed. Four interviews with minority employees are then analysed in depth, showing how their...
2.
Successful female expatriates as agents: Positioning oneself through gender, hierarchy and culture - JANSSENS, Maddy; CAPPELLEN, Tineke; ZANONI, Patrizia
While most studies on female expatriates take a structural approach, this study considers female expatriates as active agents, capable of producing effective professional identities when interacting with men. We propose that female expatriates are agents who selectively interpret interactions with male actors and actively position themselves within these interactions. Within these two processes of interpreting and positioning, we examine how they draw from gender, hierarchy and culture as three power-laden identity discourses that not only constrain but also enable their actions. Through the analysis of in-depth interviews with successful female expatriates, we show how these women counter their (perceived) lower...
3.
Purity of epitaxial cubic BoronNitride films on (001) Diamond - A prerequisite for their doping - Yin, H.; BOYEN, Hans-Gerhard; Ziemann, P.; Dohuard, B.; Houssiau, L.; Renaux, F.; Hecq, M.; Bittencourt, C.
Phase pure cubic BoronNitride (c-BN) films were epitaxially grown on (001) Diamond substrates at 900 degrees C and analyzed for purity by taking X-ray Photoelectron Spectroscopy (XPS) as well as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) depth profiles. No metallic impurities could be detected within the resolution limit of ToF-SIMS corresponding to some ppm. The films, however, still contain typically 0.5 at. % carbon and 1 at.% oxygen, which both can be traced back to the boron sputter target. All as-prepared c-BN films, with and without additional sputter cleaning of their surface, exhibit a p-type conductivity, which can be attributed...
4.
Rhodium deposition onto a 4-mercaptopyridine SAM on Au(111) - Manolova, M.; Kayser, M.; Kolb, D. M.; BOYEN, Hans-Gerhard; Ziemann, P.; Mayer, D.; Wirth, A.
The application of a recently developed method for the deposition of Pd and Pt on top of a SAM, has been successfully extended to Rh, thus proving the versatility of the new concept. Experimental evidence from cyclic voltammetry, in situ STM and ex situ X-ray photoemission spectroscopy is presented for the deposition of monoatomic high rhodium islands onto a 4-mercaptopyridine self-assembled monolayer on a Au(1 1 1) electrode. By repetitive complexation of the Rh ions to the ring-nitrogen and reduction in a Rh-ion free solution, an almost completely covered SAM is obtained. The consequences of making contacts for molecular electronics...
5.
Enhanced orbital magnetism in Fe50Pt50 nanoparticles - Antoniak, C.; Lindner, J.; Spasova, M.; Sudfeld, D.; Acet, M.; Farle, M.; Fauth, K.; Wiedwald, U.; BOYEN, Hans-Gerhard; Ziemann, P.; Wilhelm, F.; Rogalev, A.; Sun, Shouheng
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 metallic state. After thermal treatment of the metallic particles, the coercive field increased by a factor of 6, the orbital magnetic moment at the Fe site increased by 330% and is reduced at the Pt site by 30%, while the effective spin moments did not change....
6.
Diversity management as identity regulation in the Post-Fordist productive space - Zanoni, Patrizia; Janssens, Maddy
Breaking with previous literature, the chapter approaches diversity management as a mode of managerial control through identity regulation within the post-Fordist productive space. Such space is characterized by spatio-temporal discontinuities at the international, organizational and work levels which render traditional direct modes of control increasingly ineffective. Management increasingly controls labour indirectly by regulating workers’ identities as to make them develop a sense of the self conducive to the attainment of organizational goals. Diversity management regulates identity in three main ways, by defining workers as: individual entrepreneurial subjects, members of specific socio-demographic groups, and members of the organization. While the first...
7.
Cavity ring-down spectroscopy of metallic gold nanoparticles - Gilb, S.; Hartl, K.; Kartouzian, A.; Peter, J.; Heiz, U.; BOYEN, Hans-Gerhard; Ziemann, P.
The optical properties of supported gold nanoparticles with sizes of 1.3 nm, 1.6 nm, 2.5 nm, and 2.9 nm have been studies by using cavity ring-down spectroscopy in the photon energy range between 1.8 eV and 3.0 eV. The obtained results show the possibility to obtain optical information of nanoassembled materials with high sensitivity. The experimental findings are compared to calculations using Mie-Drude theory. Whereas the broadening of the surface plasmon resonance with decreasing size is well described by this model, the observed blue-shift of the surface plasmon resonance contradicts the predictions of the Mie-Drude theory. The latter effect can...
8.
Magnetic moment of Fe in oxide-free FePt nanoparticles - Dmitrieva, O.; Spasova, M.; Antoniak, C.; Acet, M.; Dumpich, G.; Kaestner, J.; Farle, M.; Fauth, K.; Wiedwald, U.; BOYEN, Hans-Gerhard; Ziemann, P.
We present results of x-ray absorption spectroscopy and x-ray magnetic circular dichroism investigations at the L-3,L-2 edges of Fe in FePt nanoparticles. Plasma treated, oxide-free FePt nanoparticles with a high degree of L1(0) ordering and a mean diameter of about 6 nm were produced by gas phase condensation followed by in situ flight annealing. The presence of the L1(0) phase is observed by high resolution transmission electron microscopy. Compared to chemically disordered A1 FePt particles of similar size and composition, we find a fourfold enhanced orbital magnetic moment mu(L)=0.19 (+/- 0.04)mu(B), a nearly unchanged effective spin magnetic moment mu(eff)(S)=2.21 (+/-...
9.
Controlling the interparticle spacing of Au-salt loaded micelles and Au nanoparticles on flat surfaces - Bansmann, J.; Kielbassa, S.; Hoster, H.; Weigl, F.; BOYEN, Hans-Gerhard; Wiedwald, U.; Ziemann, P.; Behm, R. J.
The self-organization of diblock copolymers into micellar structures in an appropriate solvent allows the deposition of well ordered arrays of pure metal and alloy nanoparticles on flat surfaces with narrow distributions in particle size and interparticle spacing. Here we investigated the influence of the materials (substrate and polymer) and deposition parameters (temperature and emersion velocity) on the deposition of metal salt loaded micelles by dip-coating from solution and on the order and inter-particle spacing of the micellar deposits and thus of the metal nanoparticle arrays resulting after plasma removal of the polymer shell. For identical substrate and polymer, variation of...
10.
Lowering of the L1(0) ordering temperature of FePt nanoparticles by He+ ion irradiation - Wiedwald, U.; Klimmer, A.; Kern, B.; Han, L.; BOYEN, Hans-Gerhard; Ziemann, P.; Fauth, K.
Arrays of FePt particles (diameter 7 nm) with mean interparticle distances of 60 nm are prepared by a micellar technique on Si substrates. The phase transition of these magnetic particles towards the chemically ordered L1(0) phase is tracked for 350 kV He+ ion irradiated samples and compared to a nonirradiated reference. Due to the large separation of the magnetically decoupled particles the array can be safely annealed without any agglomeration as usually observed for more densely packed colloidal FePt nanoparticles. The He+ ion exposure yields a significant reduction of the ordering temperature by more than 100 K. (c) 2007 American...
11.
Fabrication of ohmic Au/Cr contacts on top of cubic boron nitride films - Yin, H.; BOYEN, Hans-Gerhard; Zhang, X. -W.; Ziemann, P.
To fabricate electrical contacts on top of c-BN films, Au films were deposited through a mask by Pulsed Laser Ablation (PLD) and evaporation to allow a comparison of the mechanical stability as well as conductive behavior for both methods. Though in all cases a thin intermediate Cr layer was added to improve adhesion, it turned out that evaporated films had to be ion bombarded additionally at room temperature with 300keV Ar+ ions to guarantee mechanical stability whereas the PLD films were stable without further bombardment. The resulting IN characteristics for both types of contacts exhibit the required ohmic behavior. (c)...
12.
A micellar approach to magnetic ultrahigh-density data-storage media: Extending the limits of current colloidal methods - Ethirajan, Anitha; Wiedwald, Ulf; BOYEN, Hans-Gerhard; Kern, Birgit; Han, Luyang; Klimmer, Andreas; Weigl, Frank; Kaestle, Gerd; Ziemann, Paul; Fauth, Kai; Cai, Jun; Behm, R. Juergen; Romanyuk, Andriy; Oelhafen, Peter; Walther, Paul; Biskupek, Johannes; Kaiser, Ute
An alternative route for producing L1(0) FePt nanoparticles based on the self-organization of diblock copolymers into spherical micelles is presented. it overcomes all of the drawbacks of current colloidal strategies towards densely packed arrays of ferromagnetic FePt nanoparticles while still guaranteeing areal densities exceeding 1 Tbits inch(-2). The figure shows a sketch of the metal-salt-loaded micelles deposited on a substrate: a polystyrene shell (red) covers the poly (2-vinylpyridine) core (blue) forming a nanoreactor loaded with metal salt (yellow).
13.
From self-organized masks to nanotips: A new concept for the preparation of densely packed arrays of diamond field emitters - Weigl, Frank; Fricker, Sebastian; BOYEN, Hans-Gerhard; Dietrich, Christof; Koslowski, Berndt; Plettl, Alfred; Pursche, Oliver; Ziemann, Paul; Walther, Paul; Hartmann, Christoph; Ott, Marcel; Moeller, Martin
Diblock copolymer based gold nanoparticle arrays are used to pattern diamond and silicon surfaces on the nanoscale. Taking advantage of diblock copolymers forming spherical reverse micelles, which self-assemble into hexagonally ordered arrays when deposited onto a surface, gold nanoparticle patterns are prepared from HAuCl4 loaded poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) micelles on top of diamond and silicon. By applying these particles as nanomasks for subsequent reactive ion etching, the hexagonal pattern is transferred into the substrate resulting in a corresponding array of diamond nanotips and silicon nanopillars, respectively. In the case of B-doped diamond, these nanotips exhibit a significantly enhanced electron emissivity as...
14.
Behaviour of discontinuous gold films on SrTiO3 substrates under annealing - Beszeda, Imre; Kocsis, Tamas; Imreh, Gergely; Weigl, Frank; BOYEN, Hans-Gerhard; Ziemann, Paul; Beke, Dezso L.
Morphological changes of thin, discontinuous gold films on SrTiO3 substrates, resulting from evaporation in the temperature range of 11431278 K, have been investigated by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). If the gold covered fraction of the surface is small, the evaporation kinetics can be related to the desorption of adatoms. Measuring the density of the gold beads and the time dependence of the effective thickness of the film as calculated from the diameter of the beads, the following parameters have been determined: the surface diffusion length of the gold adatoms, lambda(s) (m) = (2.2(-2.0)(+26.7))...
15.
Local density of states effects at the metal-molecule interfaces in amolecular device - BOYEN, Hans-Gerhard; Ziemann, P; Wiedwald, U; Ivanova, V; Kolb, DM; Sakong, S; Gross, A; Romanyuk, A; Buttner, M; Oelhafen, P
Clarifying the nature of interactions between metal electrodes and organic molecules still represent one of the challenging problems in molecular electronics that needs to be solved in order to optimize electron transport through a molecular device. For this purpose, electronic properties at metal - molecule interfaces were studied by combining experimental and theoretical methods. Applying a novel electrochemical approach, strictly two-dimensional Pd islands were prepared on top of 4-mercaptopyridine self-assembled monolayers (4MP-SAMs) which, in turn, were deposited on (111)-oriented Au single crystals. Electron spectroscopy together with density functional theory calculations revealed strong interactions between the molecules and the islands due...
16.
Transition from anomalous kinetics toward Fickian diffusion for Si dissolution into amorphous Ge - Balogh, Zoltan; Erdelyi, Zoltan; Beke, Dezsoe L.; Langer, Gabor A.; Csik, Attila; BOYEN, Hans-Gerhard; Wiedwald, Ulf; Ziemann, Paul; Portavoce, Alain; Girardeaux, Christophe
Over the last years, several experimental and theoretical studies of diffusion kinetics on the nanoscale have shown that the time evolution (x proportional to t(c)(k)) differs from the classical Fickian law (k(c)=0.5). However, all work was based on crystalline samples or models, so far. In this letter, we report on the diffusion kinetics of a thin amorphous Si layer into amorphous Ge to account for the rising importance of amorphous materials in nanodevices. Employing surface sensitive techniques, the initial k(c) was found at 0.7 +/- 0.1. Moreover, after some monolayers of Si dissolved into the Ge, k(c) changes to the...
17.
On the morphology and stability of Au nanoparticles on TiO2(110) prepared from micelle-stabilized precursors - Kielbassa, Stefan; Haebich, Annette; Schnaidt, Johannes; Bansmann, Joachim; Weigl, Frank; BOYEN, Hans-Gerhard; Ziemann, Paul; Behm, R. Juergen
The morphology and stability of well-ordered, nanostructured Au/TiO2(110) surfaces, prepared by deposition of Au loaded micelles on TiO2(110) substrates and subsequent oxidative removal of the polymer shell in an oxygen plasma, was investigated by noncontact AFM, SEM and XPS. The resulting arrays of Au nanoparticles (particle sizes 1-5 nm) form a nearly hexagonal pattern with well-defined interparticle distances and a narrow particle size distribution. Particle size and particle separation can be controlled independently by varying the Au loading and the block-copolymers in the micelle shell. The oxygen plasma treatment does not affect the size and distance of the Au nanoparticles;...
18.
Influence of ion induced amorphicity on the diffusion of gold into silicon - Ehrhardt, J.; Klimmer, A.; Eisenmenger, J.; Mueller, Th.; BOYEN, Hans-Gerhard; Ziemann, P.; Biskupek, J.; Kaiser, U.
It is experimentally demonstrated that, after ion irradiating 60 nm thick Au films on Si substrates with 230 keV Ar+ ions, annealing conditions can be found leading to strong diffusional contrasts between bombarded and unbombarded areas. While Au readily diffuses into the bombarded part of the sample at 310 degrees C, its diffusion is still completely blocked under identical conditions in the unbombarded parts. Clear evidence is provided that this diffusional contrast is due to bombardment induced amorphization of the underlying Si substrate. The amorphous Silicon (a-Si), however, has to extend right to the Au/Si interface, since any intermediate crystalline...
19.
Substrate influence in Young's modulus determination of thin films by indentation methods: Cubic boron nitride as an example - Richter, F.; Herrmann, M.; Molnar, F.; Chudoba, T.; Schwarzer, N.; Keunecke, M.; Bewilogua, K.; Zhang, X. W.; BOYEN, Hans-Gerhard; Ziemann, P.
This paper deals with the determination of Young's modulus of thin films by indentation methods using cubic boron nitride (c-BN) as an example. This is a non-trivial task because the Young's modulus of this material comes close to that of the diamond indenter. An analysis of results from literature revealed that Young's moduli of c-BN thin films are generally distinctly smaller than bulk material values. We give reasons that this is at least to a large extent due to measuring problems, in particular the absence of a proper correction of substrate influence. In the experimental part we have used nanoindentation...
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