Sökning: "K Venkat Rao"

Hittade 5 avhandlingar innehållade orden K Venkat Rao.

  1. 1. Magnetism in Band Gap Engineered Sputtered MgxZn(1-x)O Thin Films

    Författare :Sreekanth Mahadeva; K Venkat Rao; Lyubov Belova; Mark Fox; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Magnetron co-sputtering; MgO; MgxZn 1-x O; MnxMg 1-x O; thin films; Room-temperature ferromagnetism; band gap engineering; and intrinsic defects;

    Sammanfattning : This dissertation presents a comprehensive study of the intrinsic room temperature ferromagnetism, RTFM, in technologically important thin films of ZnO, MgO, Mg@ZnO, the so-called d0–magnets that do not contain any intrinsic magnetic elements. We also present the first report on magnetism in Mn doped MgO films fabricated by dc magnetron sputtering. LÄS MER

  3. 2. 3D Magnetic Photonic Crystals : Synthesis and Characterization

    Författare :Mei Fang; K.Venkat Rao; Lyubov Belova; Rajeev Ahuja; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; magnetic photonic crystals; photonic band gaps; Fe3O4 nanoparticles; silica; Optical physics; Optisk fysik; Materials science; Teknisk materialvetenskap;

    Sammanfattning : This thesis presents the synthesis methods and the characterizations of magnetic Fe3O4 nanoparticles, silica spheres with Fe3O4 nanoparticles embedded, and three dimensional magnetic photonic crystals (MPCs) prepared from the spheres. The structure, material composition, magnetic and optical properties, photonic band gaps (PBGs), as well as how these properties depend on the concentration of the magnetic nanoparticles, are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), superconducting quantum interference device (SQUID), Faraday rotation (FR) and optical spectrophotometers. LÄS MER

  4. 3. Properties of Multifunctional Oxide Thin Films Despostied by Ink-jet Printing

    Författare :Mei Fang; Lyubov Belova; K. Venkat Rao; Gillian Gehring; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ink-jet printing; oixde; thin film; ink; suspension; dye sensitized solar cell; functional properties; magnetism; diluted magnetic semiconductors;

    Sammanfattning : Ink-jet printing offers an ideal answer to the emerging trends and demands of depositing at ambient temperatures picoliter droplets of oxide solutions into functional thin films and device components with a high degree of pixel precision. It is a direct single-step mask-free patterning technique that enables multi-layer and 3D patterning. LÄS MER

  5. 4. Functional Metallic Glasses

    Författare :Ansar Masood; Lyubov Belova; K. Venkat Rao; Lars Arnberg; KTH; []
    Nyckelord :Bulk Metallic glasses; glass forming ability; soft magnetism; thin films; magnetic properties; magnetic hardening; plasticity; biocompatibility;

    Sammanfattning : For decades, Metallic Glass, with its isotropic featureless structure while exhibiting outstanding mechanical properties was possible only at a high rate of quenching and with at least one dimension in the submicron regime.  This limitation was overcome with the discovery of Bulk Metallic glasses, BMGs, containing three or more elements following the additional two empirical rules of optimum geometric size differences and negative energy of mixing among the constituent elements. LÄS MER

  7. 5. Multifunctional magnetic materials prepared by Pulsed Laser Deposition

    Författare :Sandeep Nagar; Lyuba Belova; K. Venkat Rao; Prashanth Kamath; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic materials; thin films; pulsed laser depsoition; spintronics; chromites; MgO; NEMS; MEMS;

    Sammanfattning :      Pulsed LASER deposition (PLD) is widely recognized as excellent deposition technique owing to stoichiometric transfer of target material, easy preparation and high quality. Thin films from few nanometers to micrometer regime can be fabricated with equal ease. LÄS MER