Temperature dependence of the magnetization processes in Co/Al oxide/Permalloy trilayers

The magnetization process of Co/Al oxide/Py trilayers and its evolution with the temperature have been analyzed. The particular behavior of the Co layers, including the shift of the hysteresis loops and a coercivity increase with the decrease of temperature, is related with the apparition of a CoO layer at the Co/Al-oxide interface

Particle growing mechanisms in Ag-ZrO2 and Au-ZrO2 granular films obtained by pulsed laser deposition

Thin films consisting of Ag and Au nanoparticles embedded in amorphous ZrO2 matrix were grown by pulsed laser deposition in a wide range of metal volume concentrations in the dielectric regime (0.08<x(Ag)<0.28 and 0.08<x(Au)<0.52). High resolution transmission electron microscopy (TEM) showed regular distribution of spherical Au and Ag nanoparticles having very sharp interfaces with the amorphous matrix. Mean particle size determined from X-ray diffraction agreed with direct TEM observation. The silver mean diameter increases more abruptly with metal volume content than that corresponding to gold particles prepared under the same conditions. Two mechanisms of particle growing are observed: nucleation and particle coalescence, their relative significance being different in both granular systems, which yields very different values of the percolation threshold (xc(Ag)~0.28 and xc(Au)~0.52).Comment: 6 figure

A Real-Time Ethernet Network at Home

This paper shows the current state of our research into a home network which provides both real-time and non-real-time capabilities for one coherent, distributed architecture. It is based on a new type of real-time token protocol that uses scheduling to achieve optimal token-routing in the network. Depending on the scheduling algorithm, bandwidth utilisations of 100% are possible. Token management, to prevent token-loss or multiple tokens, is essential to support a dynamic, plug-and-play configuration. Our network will support inexpensive, small appliances as well as more expensive, large appliances. Small appliances, like sensors, would contain low-cost, embedded processors with limited computing power, which can handle lightweight network protocols. All other operations can be delegated to other appliances that have sufficient resources. This provides a basis for transparency, as it separates controlling and controlled object

Antiferromagnetic correlations in Fe-Cu granular alloys: the role of the surface structure

Fe precipitates in a Cufcc matrix, prepared using the Bridgeman method and with an average composition of Cu97Fe3, displayed the coexistence of ferromagnetism ~FM!, spin glass-like ~SGL! behavior and antiferromagnetic ~AFM! correlations. The two former contributions may be attributed, respectively, to the segregation of FM, a-Febcc precipitates and to the few Fe spins distributed in the matrix. The annealing procedures increased the FM contribution and, as particle growth and phase segregation took place, the SGL behavior progressively disappeared. Results from high resolution transmission electron microscopy ~HRTEM!, x-ray photoelectron spectroscopy ~XPS!, and electron energy-loss spectroscopy ~EELS! suggest that the AFM correlations are due to the a-Fe particles that show a surface layer of a few nanometers in thickness, of either FeO and/or g-Fefcc . XPS and EELS measurements confirm the presence of FeO; however, the latter is only tentatively suggested by the HRTEM analysis of the particle/matrix interfaces

Transitie van een psychogeriatrische dagbehandeling in het verpleeghuis naar een laagdrempelige dagbehandeling in de wijk: een pilotonderzoek

Achtergrond In deze studie wordt de transitie van een reguliere psychogeriatrische dagbehandeling in het verpleeghuis naar laagdrempelige psychogeriatrische dagbehandeling met mantelzorgondersteuning (LPD-plus MO) in de wijk op de voet gevolgd. Het bewezen effectieve Model Ontmoetingscentra vormde het uitgangspunt bij de transitie. Methode Door middel van kwalitatieve analyse van documenten en interviews met sleutelfiguren (n = 11) worden factoren opgespoord die de overgang van de oude naar de nieuwe vorm van dagbehandeling bevorderen of belemmeren. Bij deelnemers en mantelzorgers die langer dan 6 maanden gebruik maken van het ondersteuningsaanbod wordt de tevredenheid over het nieuwe aanbod gepeild. Resultaten Verschillende kenmerken van LPD-plus MO blijken de samenwerking met andere zorg- en welzijnsaanbieders in de regio te bevorderen, zoals: de laagdrempelige locatie, de sociale integratie in de buurt en de focus op gecombineerde ondersteuning van zowel de persoon met dementie als de mantelzorger. Een goede samenwerking met andere zorg- en welzijnsorganisaties, en een geschikte locatie vergemakkelijken de implementatie. De aanwezigheid van concurrerend aanbod in de regio, zoals ontmoetingscentra voor mensen met dementie en hun mantelzorgers, belemmeren de werving van deelnemers voor de LPDplus MO. Deelnemers en mantelzorgers zijn over het algemeen tevreden over het ondersteuningsprogramma. Conclusie en discussie De transitie is succesvol verlopen en levert andere reguliere dagbehandelingen tips op voor de transitie naar LPD-plus MO

Martensitic transition and magnetoresistance in a Cu-Al-Mn shape memory alloy. Influence of aging

We have studied the effect of ageing within the miscibility gap on the electric, magnetic and thermodynamic properties of a non-stoichiometric Heusler Cu-Al-Mn shape-memory alloy, which undergoes a martensitic transition from a $bcc$-based ($\beta$-phase) towards a close-packed structure ($M$-phase). Negative magnetoresistance which shows an almost linear dependence on the square of magnetization with different slopes in the $M$- and $\beta$-phases, was observed. This magnetoresistive effect has been associated with the existence of Mn-rich clusters with the Cu$_2$AlMn-structure. The effect of an applied magnetic field on the martensitic transition has also been studied. The entropy change between the $\beta$- and $M$-phases shows negligible dependence on the magnetic field but it decreases significantly with annealing time within the miscibility gap. Such a decrease is due to the increasing amount of Cu$_2$MnAl-rich domains that do not transform martensitically.Comment: 9 pages, 9 figures, accepted for publication in PR