Characterization of Room-Temperature Ferromagnetic Zn1-xCoxO Nanowires PDF Download

Author: Yi-Ching Ou
Publisher:
ISBN:
Category : Science
Languages : en
Pages :

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Characterization of Room-Temperature Ferromagnetic Zn1-xCoxO Nanowires.

Author: Paola Prete
Publisher: IntechOpen
ISBN: 9789537619794
Category : Science
Languages : en
Pages : 428

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Book Description
This volume is intended to orient the reader in the fast developing field of semiconductor nanowires, by providing a series of self-contained monographs focusing on various nanowire-related topics. Each monograph serves as a short review of previous results in the literature and description of methods used in the field, as well as a summary of the authors recent achievements on the subject. Each report provides a brief sketch of the historical background behind, the physical and/or chemical principles underlying a specific nanowire fabrication/characterization technique, or the experimental/theoretical methods used to study a given nanowire property or device. Despite the diverse topics covered, the volume does appear as a unit. The writing is generally clear and precise, and the numerous illustrations provide an easier understanding of the phenomena described. The volume contains 20 Chapters covering altogether many (although not all) semiconductors of technological interest, starting with the IV-IV group compounds (SiC and SiGe), carrying on with the binary and ternary compounds of the III-V (GaAs, AlGaAs, GaSb, InAs, GaP, InP, and GaN) and II-VI (HgTe, HgCdTe) families, the metal oxides (CuO, ZnO, ZnCoO, tungsten oxide, and PbTiO3), and finishing with Bi (a semimetal).

Author: Ángel Roberto Ruiz Reyes
Publisher:
ISBN:
Category :
Languages : en
Pages : 170

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Publisher: DEStech Publications, Inc
ISBN: 1605951773
Category : Technology & Engineering
Languages : en
Pages : 776

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The conference aims to provide an excellent international academic forum for all the researchers, practitioner, students and teachers in related fields to share their knowledge and results in theory, methodology and application on mechanics and materials engineering. ICMME2014 features unique mixed topics of Mechanics, Materials Science and Materials Processing Technology, Emerging materials and other related ones. The ICMME2014 proceeding tends to collect the most up-to-date, comprehensive, and worldwide state-of-art knowledge on mechanics and materials engineering. All the accepted papers have been submitted to strict peer-review by 2–4 expert referees, and selected based on originality, significance and clarity for the purpose of the conference. The conference program is extremely rich, profound and featuring high-impact presentations of selected papers and additional late-breaking contributions. We sincerely hope that the conference would not only show the participants a broad overview of the latest research results on related fields, but also provide them a significant platform for academic connection and exchange.

Author: Andreas Öchsner
Publisher: Springer Science & Business Media
ISBN: 364214697X
Category : Technology & Engineering
Languages : en
Pages : 368

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The development of nanomaterials opens the possibility for new materials with outstanding properties compared to classical engineering materials. These materials can find applications in different fields such as medical treatment or structural mechanics. This monograph focuses on two major groups of nanomaterials, i.e.nanoparticels and nanocomposites. Nanopartices, for example in the form of hollow particles, allow for new possibilities in drug delivery. Different aspects of nanoparticles ranging from manufacturing to modeling and simulation are covered. Nanocomposite materials are formed by mixing two or more dissimilar materials at the nanoscale in order to control and develop new and improved structures and properties. The properties of nanocomposites depend not only on the individual components used but also on the morphology and the interfacial characteristics. Nanocomposite coatings and materials are one of the most exciting and fastest growing areas of research and novel properties being continuously developed which are previously unknown in the constituent materials. Thus, the second part of this monograph gives an overview on the latest developments in the area of composites and coatings based on nanomaterials.

Author: Battogtokh Jugdersuren
Publisher:
ISBN: 9781109491036
Category : Ferromagnetism
Languages : en
Pages : 109

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Nanotechnology offers tremendous potential for future technology. A better understanding of ferromagnetism, half-metallicity and magnetostriction on the smallest scales are expected to improve technological performance. Processing and characterization of nanostructured materials, therefore, are central in modern solid state physics. One of the techniques to grow nanostructures is electrospinning which offers simplicity, low cost and flexibility. This dissertation focuses on functionally different colossal magnetoresistance strontium and calcium doped lanthanum manganites and magnetostrictive iron-gallium nanowires. We have tailored the conventional electrospinning method to grow high quality manganites and iron-gallium nanowires below 100 nm in diameter for the first time. We have shown that these ferromagnetic nanostructures can be grown parallel to one another for understanding the basic physics as well as for fabricating advanced device structures. Single nanowire devices were fabricated by electron-beam lithography. Details of the growth, morphology, structure and magnetic characterization, device fabrication and performance of the devices will be discussed in this thesis. Manganite nanowires have been grown by anodized alumina oxide template and by the pulsed laser deposition methods by other groups, nanowires grown from these techniques are difficult to use for device fabrication. Devices based on electrospun manganite and iron-gallium nanowires have shown improved electrical and magneto-transport properties. Half-metallic lanthanum-strontium manganite nanowires with 80- 300 nm in diameters display enhanced magnetoresistance behavior at room temperature and the large magnetoresistance is exhibited at low magnetic field which will play an important role for creation of novel-next generation devices. Although inter-metallic, bulk iron-gallium is one of the highly attractive magnetostrictive materials, at nano level, it is very rarely studied due to difficulty of growing high-quality materials. Alumina templates or by melt-spinning are only methods applied so far to grow iron-gallium wires. Melt-spinning yields microscale ribbons and the growth using templates results in nanowires with varying stoichiometry over the entire length of the nanowire. This work has produced high quality, stoichiometric, parallel bundles of iron-gallium nanowires with diameters varying from 80-500 nm. These iron gallium nanowires exhibit enhanced magnetic properties. Devices with bundles of iron-gallium nanowires are explored for various applications such as submarine sonar, as highly sensitive magnetic sensors and nanoscale valves.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

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Author: PoChing Tsai
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Ferromagnetic nanocrystals with shape anisotropy have drawn great attention in the past decades because of their unique magnetic properties and for their potential applications in ultra-high-density magnetic recording media, exchange-coupled nanocomposite magnets and related nanodevices. In this thesis, synthesis and characterixation of ferromagnetic CoNi and CoFe nanowires are reported. CoNi nanocrystals with different size, shape and composition were successfully synthesized via a catalyst chemical solution method. It was found out that the structure and morphology can be controlled by altering the NaOH concentration, and the elongation of the nanowires can be adjusted by changing surfactants ratio and catalyst amount. Unlike the CoNi, CoFe nanocrystals were prepared by a non-catalyst chemistry solution method. The particle size and shape are controlled by varying parameters such as solvent amount, surfactant ratio, reducing agent and heating rate. Morphological, structural, and compositional characterizations of the nanoparticles were performed by using Transmission Electron Microscopy (TEM), high resolution TEM (HRTEM), and X-Ray Diffractometer (XRD). Magnetic properties of nanoparticles of different size were studied by Alternating Gradiant Magnetometer (AGM).

Author: Usha Philipose
Publisher:
ISBN: 9780494399774
Category :
Languages : en
Pages : 376

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This thesis describes a catalytic growth approach to synthesize semiconductor nanowires with good control over their physical dimensions, chemical composition, and optical/electronic properties. Using the Vapour-Liquid-Solid growth mechanism, gold nanoclusters serve as the catalytic sites directing the growth of crystalline Zinc Selenide (ZnSe), Zinc Oxide (ZnO) and Zinc Sulphide (ZnS) nanowires with length of several microns and diameters varying from 15 nm to 100 nm. The effect of doping of these nanowires with transition elements such as manganese (Mn) has been studied. In this effort, the first successful attempt at synthesizing room temperature ferromagnetic nanowires has been realized. Above room temperature ferromagnetism has been observed for the first time in dilute Mn-doped crystalline ZnO nanowires. From the observed saturation magnetization, the magnetic moment per Mn atom is estimated to be in the range of 0.3 muB to 1.2 microB. The results of this thesis demonstrate that II-VI semiconductor nanowires such as ZnSe and ZnO can function as nanoscale devices and are promising for important applications in optoelectronic and spintronic devices. Electrical transport studies on an array of ZnSe nanowires confirm that there exists a non-uniform carrier distribution along the nanowires leading to 'super-linear' current-voltage behaviour with carrier mobilities comparable to that of bulk material. Photoconductivity measurements on ZnSe nanoribbons show that they are of good quality, enabling realization of a nanoscale photodetector with a peak efficiency of 43%. Spectral response of photoconductivity had a threshold character with edge corresponding to the ZnSe bandgap, which makes it an ideal candidate for blue and ultraviolet light detection. The morphology and properties of the nanowires were found to be strongly dependent on growth conditions. Optical characterization by photoluminescence spectroscopy show that the spectra is dominated by near band edge emission for low defect density nanowires in contrast to the high level of defect related emission from high defect density nanowires. The growth parameters were optimized leading to the synthesis of nanowires with minimum defect concentration.

Author: Dr. Orhan Yalçın
Publisher: BoD – Books on Demand
ISBN: 9535111868
Category : Science
Languages : en
Pages : 252

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Book Description
The book Ferromagnetic Resonance - Theory and Applications highlights recent advances at the interface between the science and technology of nanostructures (bilayer-multilayers, nanowires, spinel type nanoparticles, photonic crystal, etc.). The electromagnetic resonance techniques have become a central field of modern scientific and technical activity. The modern technical applications of ferromagnetic resonance are in spintronics, electronics, space navigation, remote-control equipment, radio engineering, electronic computers, maritime, electrical engineering, instrument-making and geophysical methods of prospecting.