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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Novel room temperature ferromagnetic semiconductors

    Författare :Amita Gupta; KTH; []
    Nyckelord :;

    Sammanfattning : In today's information world, bits of data are processed bysemiconductor chips, and stored in the magnetic disk drives.But tomorrow's information technology may see magnetism (spin)and semiconductivity (charge) combined in one 'spintronic'device that exploits both charge and 'spin' to carry data (thebest of two worlds). LÄS MER

  3. 2. 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

  4. 3. 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

  5. 4. Synthesis, Nuclear Structure, and Magnetic Properties of some Perovskite Oxides

    Författare :Mehreteab Tseggai; Per Nordblad; Roland Tellgren; Torbjörn Gustafsson; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Magnetic Perovskites; Neutron powder diffraction; SQUID; Synthesis; Nuclear structure; Antiferromagnetism; Ferromagnetism; Superexchange; Double exchange; Colossal magnetoresistance; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Synthesis, nuclear structure, and magnetic properties of the perovskites: Nd0.7-xMgxSr0.3MnO3 (x=0.0, 0. LÄS MER

  7. 5. Functional Metal Oxide Materials Deposited by Inkjet Printing Technique

    Författare :Yan Wu; Lyubov Belova; Gillian Gehring; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inkjet printing; photoconductivity; ZnO; Al-ZnO; composite; electron transfer; CdS; field effect transistor; photosensitive; RT do-ferromagnetism; Mn-doped ZnO; MgO; Materials science; Teknisk materialvetenskap;

    Sammanfattning : This thesis presents a comprehensive study of the intrinsic room temperature ferromagnetism in 85 to 100nm thin films produced by in situ deposition of industrially important pristine MgO and ZnO by inkjet printing. It is suggested that the observed long range magnetic order, the so-called do magnetism in these oxides arises from cation vacancies. LÄS MER