In this work, a novel approach is suggested to grow bilayer fibers by combining electrospinning and atomic layer deposition (ALD). Polyvinyl alcohol (PVA) fibers are obtained by electrospinning and subsequently covered with thin AlO deposited at a low temperature by ALD. To burn the PVA core, the fibrous structures are subjected to high-temperature annealing.
View Article and Find Full Text PDFHexaferrites have long been the object of extensive studies because of their great possibility for applications-permanent magnets, high-density recording media, microwave devices, in biomedicine, to name but a few. Lately, many researchers' efforts have been focused on the existence of the magneto-electric effect in some hexaferrite systems and the appealing possibility of them being used as single-phase multiferroic and magneto-electric materials. As indicated by theoretical analyses, the origin of the large magneto-electric effect can be sought in the strong interaction between the magnetization and the electric polarization that coexist in insulators with noncollinear magnetic structures.
View Article and Find Full Text PDFHere, we report results on the magnetic and microwave properties of polycrystalline Y-type hexaferrite synthesized by sol-gel auto-combustion and acting as a filler in a composite microwave-absorbing material. The reflection losses in the 1-20 GHz range of the Y-type hexaferrite powder dispersed homogeneously in a polymer matrix of silicon rubber were investigated in the absence and in the presence of a magnetic field. A permanent magnet was used with a strength of 1.
View Article and Find Full Text PDFThe data presented has to do with identifying the various phases arising during the synthesis of the Y-type hexaferrite series BaSrZnNiFeO by auto-combustion that we deem important for their microstructural and magnetic properties. The data and the related analyses support the research paper "Ni-substitution effect on the properties of BaSrZnNiFeO powders" [1]. Thus, the parameters are presented of the phases appearing after auto-combustion and after the initial annealing at 800 °C, namely, crystal cell and crystallite size.
View Article and Find Full Text PDFBaMgCoFeO was prepared in powder form by sonochemical co-precipitation and examined by X-ray diffraction, Mössbauer spectroscopy and magnetization measurements. Careful XRD data analyses revealed the Y-type hexaferrite structure as an almost pure phase with a very small amount of CoFeO as an impurity phase (about 1.4%).
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