Sökning: "oxygen ordering"

Visar resultat 16 - 20 av 24 avhandlingar innehållade orden oxygen ordering.

1. 16. Defect Induced Room-Temperature Ferromagnetism in ZnO and MgO Thin FIlms and Device Development

   Författare :Mukes Kapilashrami; Lyuba Belova; E Dan Dahlberg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Room-temperature ferromagnetism; intrinsic defects; un-balanced balanced magnetron sputtering; magnetic anisotropy and photoconductivity; Materials science; Teknisk materialvetenskap;

   Sammanfattning : This thesis presents the discovery of defect induced room-temperature ferromagnetism in industrially important ZnO and MgO thin films, and establishes from a systematic study, in both ZnO and MgO films, the unique phenomenon of the sequences of transitions from ferromagnetism to para-, and eventually the well known diamagnetism of the bulk as a function of film thickness. Highly oriented and high quality dense thin films of ZnO and MgO have been deposited by reactive (balanced) magnetron sputtering under different ambience conditions and deposition temperatures. LÄS MER

3. 17. 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

4. 18. Molecular design, synthesis and performance evaluation of phenothiazine-based small molecules for efficient organic solar cells

   Författare :Srikanth Revoju; Bertil Eliasson; Haining Tian; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic solar cell; small molecule donors; phenothiazine; power conversion efficiency; organisk kemi; Organic Chemistry;

   Sammanfattning : Photovoltaics offers one of the most promising routes to generate electricity in a clean way. As an emerging technology in photovoltaics, organic solar cells (OSC) have attracted a great deal of attention owing to their potential low-cost, lightweight, flexibility and solution processability. LÄS MER

5. 19. Understanding Composition–Structure–Bioactivity Correlations in Bioactive Glasses

   Författare :Yang Yu; Mattias Edén; Laurent Delevoye; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bioactive glasses; Phosphosilicate glasses; Borophosphosilicate glasses; Solid-state NMR spectroscopy; Glass structure; Fourier-transform infrared spectroscopy; Hydroxyapatite; Amorphous calcium phosphate; Apatite formation; In vitro bioactivity testing; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : Bioactive glasses integrate with bone/tooth tissues by forming a layer of hydroxy-carbonate apatite (HCA), which mimics the composition of bone mineral. In the current thesis, we investigated composition–structure–bioactivity correlations of phosphosilicate and borophosphosilicate (BPS) glasses. LÄS MER

7. 20. Molecular Interaction of Thin Film Photosensitive Organic Dyes on TiO2 Surfaces

   Författare :Shun Yu; Mats Göthelid; Chassé Thomas; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photoelectron spectroscopy; X-ray absorption spectroscopy; organic semiconductor; oxides; adsorption; dye sensitization; electronic structure; charge transfer;

   Sammanfattning : The photosensitive molecule adsorption on titanium dioxide (TiO2) forms the so-called “dye sensitized TiO2” system, a typical organic/oxide heterojunction, which is of great interest in catalysis and energy applications, e.g. dye-sensitized solar cell (DSSC). Traditionally, the transition metal complex dyes are the focus of the study. LÄS MER