Journal: Journal of Materials Science

Abbreviation

J. Mater. Sci.

Publisher

Springer

Journal Volumes

ISSN

0022-2461
1573-4803

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Publications 1 - 10 of 43
  • Recent progress on the study of the microstructure and mechanical properties of ECAE copper
    Item type: Journal Article
    Dalla Torre, Florian H.; Gazder, Azdiar A.; Pereloma, Elena V.; et al. (2007)
    Journal of Materials Science
  • High frequency characterization of Si3N4 dielectrics for artificial magnetoelectric devices
    Item type: Journal Article
    Vijayakumar, Jaianth; Gaspar, Marcos; Maurel, Laura; et al. (2022)
    Journal of Materials Science
    Charge mediated magnetoelectric coupling mechanism in artificial multiferroics originates from interfacial charge modulation or ionic movement at a magnetic/dielectric interface. Despite the existence of several dielectric/ferroelectric systems that can be used in charge mediated artificial multiferroic systems, producing suitable systems with fast time responses still remains a challenge. Here we characterize the frequency response of stoichiometric and non-stoichiometric (low strain) Si3N4 thin film membranes, which can potentially be used as the dielectric layer in magnetoelectric devices, to determine the impact of depletion layers, charge traps and defect mobility on the high frequency (up to 100 MHz) interfacial charge modulation via screening. We find that the dielectric/magnetoelectric properties are largely dominated by extrinsic doping due to point defects. In particular, we find that non-stoichiometric Si(3)N4( )has a dielectric behaviour that is dominated by charge traps and/or mobile ions. However, stoichiometric Si3N4 membranes show a reversible response to the applied bias electric field consistent with a doped semiconductor behaviour; at high frequencies, the intrinsic dielectric behaviour is reached, indicating that it may be suitable for high frequency magnetoelectric device applications. Our results show that minimising the impact of defects on the dielectric properties of magnetoelectric heterostructures is an important prerequisite for obtaining a high frequency magnetoelectric response.
  • Chemical, water vapour sorption and ultrastructural analysis of Scots pine wood thermally modified in high-pressure reactor under saturated steam
    Item type: Journal Article
    Kymäläinen, Maija; Ben Mlouka S.; Belt, Tiina; et al. (2018)
    Journal of Materials Science
  • Influence of varnishing on the vibro-mechanical properties of wood used for violins
    Item type: Review Article
    Lämmlein, Sarah L.; Mannes, David; Van Damme, Bart; et al. (2019)
    Journal of Materials Science
  • Monitoring of stress–strain evolution in thin films by reflection anisotropy spectroscopy and synchrotron X-ray diffraction
    Item type: Journal Article
    Wyss, Andreas; Sologubenko, Alla; Mishra, Nilesha; et al. (2017)
    Journal of Materials Science
    With progressing miniaturization of modern electronic devices, interconnects become increasingly smaller. Additionally, as electronic devices move away from rigid substrates toward flexible ones, understanding their mechanical and structural stability is becoming crucial. In this work, a thorough mechanical characterization of copper thin films deposited on flexible substrates was performed with two techniques, namely well-established synchrotron X-ray diffraction (sXRD) and the rather new usage of reflectance anisotropy spectroscopy (RAS) for mechanical characterization of thin films. The comparison of these two techniques shows that RAS can be reliably used for the accurate and prompt yield stress measurements. The acquisition time of RAS is much faster than that of sXRD: 1 second per data point compared to several seconds per data point for sXRD experiments. Moreover, the signal-to-noise ratio of the RAS data is much higher than that of the sXRD. Our results show that yield stress of Cu films increases with the decrease in the film thickness, going from 352 MPa for a 500 nm films to 793 MPa for a 50 nm thick film. Microstructure analyses of the films by electron microscopy allowed correlation of the mechanical behavior of the films to their grain morphologies. We have shown that RAS can supplement sXRD measurements due to a faster acquisition rate which allowed us to analyze the creep behavior of our copper thin film at different strain rates.
  • Elevated and cryogenic temperature micropillar compression of magnesium–niobium multilayer films
    Item type: Journal Article
    Thomas, Keith; Mohanty, Gaurav; Wehrs, Juri; et al. (2019)
    Journal of Materials Science
  • Melt-spun poly(tetrafluoroethylene) fibers
    Item type: Journal Article
    Goessi, Matthias; Tervoort, Theo A.; Smith, Paul (2007)
    Journal of Materials Science
  • Processing and characterization of nanofibrillated cellulose/layered silicate systems
    Item type: Journal Article
    Ho, T. T. T.; Ko, Y. S.; Zimmermann, T.; et al. (2012)
    Journal of Materials Science
  • The influence of constrictivity on the effective transport properties of porous layers in electrolysis and fuel cells
    Item type: Journal Article
    Holzer, L.; Wiedenmann, D.; Münch, B.; et al. (2013)
    Journal of Materials Science
  • Bioactive glass containing silicone composites for left ventricular assist device drivelines: role of Bioglass 45S5® particle size on mechanical properties and cytocompatibility
    Item type: Journal Article
    Cohrs, Nicholas H.; Schulz-Schönhagen, Konstantin; Jenny, Florian; et al. (2017)
    Journal of Materials Science
    Aside its historical use in contact with bone and teeth, an increasing number of studies use bioactive glasses (BG) in contact with soft tissue. BG could provide solutions for various medical problems. This study presents a first evaluation, whether BG containing silicone elastomers are a suitable material for left ventricular assist device drivelines and could enhance skin biointegration thereof. Three different nano- or microparticles of BG45S5® were incorporated into medical grade silicone elastomer, and thin films of the composites were manufactured. Physicochemical, mechanical and in vitro experiments using primary human dermal fibroblasts were used to evaluate the nano- and microcomposites. The incorporation of BG particles reduced the tensile strength at break and percent elongation at break of the composites and increased the stiffness of the material. Especially, the incorporation of nanosized BG decreased the percent elongation at break after immersion in SBF due to agglomerate formation and increased hydroxyapatite formation compared to commercially available microparticles. The cytocompatibility of BG containing composites increased significantly with increasing particle concentration. A clear trend regarding particle size was not observed. In general, the simple incorporation of particles into medical grade silicone elastomer allowed an easy modification of the mechanical properties and improvement in bioactivity (assessed by hydroxyapatite formation) of the material. The choice of either nano- or microparticles depends on the specific application and requirements for the material, as different particle types show different advantages and disadvantages.
Publications 1 - 10 of 43