Sökning: "magnesium diboride"

Hittade 5 avhandlingar innehållade orden magnesium diboride.

  1. 1. MgB2 hot-electron bolometer mixers for sub-mm wave astronomy

    Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hot-electron bolometer; gain bandwidth; noise bandwidth; thin film; electron-phonon interaction; noise temperature; THz detector; conversion gain; mixer; magnesium diboride; superconductor;

    Sammanfattning : Spectroscopy and photometry in the terahertz (THz) range of remote space objects allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. Due to high spectral resolution, THz heterodyne receivers al- low for studying dynamical properties of space objects manifested in doppler-shifted emission lines. LÄS MER

  3. 2. Magnesium Diboride (MgB2) and Ca-doped YBa2Cu3O7-? : Thin Films and Devices. Fabrication and Characterization

    Författare :Anayesu Malisa; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ca-doped YBa2Cu3O7-?; MgB2; bicrystal; superconductor; nanobridge; thin film; Josephson effect; Josephson junction;

    Sammanfattning : Magnesium diboride (MgB2) is a superconductor with an exceptionally high transition temperature, Tc, of 39 K. This work describes deposition of high quality and superconducting films of MgB2 for electronic applications. Experiments on Ca-doped YBa2Cu3O7-? films and fabrication of bicrystal Josephson junctions are also described. LÄS MER

  4. 3. Superconducting thin film and device fabrication : a study based on magnesium diboride and Ca- doped YBa2Cu3O7-

    Författare :Anayesu Malisa; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  5. 4. Superconducting THz mixers based on MgB2 film

    Författare :Stella Bevilacqua; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bolometers; IF bandwidth.; superconductors; MgB2; THz Detectors; mixers;

    Sammanfattning : Superconducting NbN hot electron bolometer (HEB) mixers are widely used in terahertz radio astronomy. Such mixers have superior performance compared to SIS and Schottky diode mixers at frequency above 1THz. However, their drawback is a limited IF bandwidth. LÄS MER

  7. 5. Study of MgB2 and YBa2Cu3O7-x Microbolometers for THz Sensing Applications

    Författare :Stella Bevilacqua; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; THz Detectors; bolometers; IF bandwidth; YBa2< sub>Cu3< sub>O7-x< sub>; Terahertz frequency; HEB; MgB2< sub>; noise; superconductors;

    Sammanfattning : In this thesis, two novel THz detectors based on magnesium diboride (MgB2)and yttrium barium copper oxide (YBa2Cu3O7-x) are presented. In particular,MgB2 superconductor is used for the investigation of hot-electron bolometer(HEB) mixers, while YBa2Cu3O7-x is explored in microbolometers for room-temperaturecoherent and incoherent detection. LÄS MER