Sökning: "Bicrystal grain boundary"

Visar resultat 6 - 10 av 10 avhandlingar innehållade orden Bicrystal grain boundary.

  1. 6. Functional Interfaces in Epitaxial YBa2Cu3O7-δ with Artificial Grain Boundary Junctions

    Författare :Henrik Pettersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The properties of superconducting devices based on grain boundaries in YBa2Cu3O7-δ (YBCO) thin films are determined by the atomic structure of the grain boundary plane. To obtain these devices based on single grain boundaries, biepitaxial fabrication techniques has been used. LÄS MER

  3. 7. Magnetic Bicrystal Junctions - a Study of Half-Metallic Manganite Grain Boundaries

    Författare :Robert Gunnarsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis presents studies on magnetic bicrystal junctions. In these, films on either side of the junction are structurally and magnetically misoriented. This type of device enables us to study junction magnetoresistance and spin polarized charge transport between ferromagnets with well defined directions of magnetization. LÄS MER

  4. 8. High-temperature superconducting magnetometers for on-scalp MEG

    Författare :Silvia Ruffieux; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; on-scalp MEG; multi-channel system; SQUID optimization; kinetic inductance magnetometer; magnetoencephalography; magnetometer; crosstalk; SQUID magnetometer calibration; high-Tc SQUID; kinetic inductance;

    Sammanfattning : In the growing field of on-scalp magnetoencephalography (MEG), brain activity is studied by non-invasively mapping the magnetic fields generated by neuronal currents with sensors that are flexibly placed in close proximity to the subject's head. This thesis focuses on high-temperature superconducting magnetometers made from YBa2Cu3Ox-7 (YBCO), which enables a reduction in the sensor-to-room temperature standoff distance from roughly 2 cm (for conventional MEG systems) down to 1 mm. LÄS MER

  5. 9. Fabrication and noise properties of high-Tc SQUIDs with multilayer superconducting flux transformers

    Författare :Maxim Chukharkin Leonidovich; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; YBCO; High-Tc SQUIDs; SQIFs; ulf-NMR; SQUID magnetometers;

    Sammanfattning : The thesis describes the development of highTc superconducting quantum interference devices (SQUIDs) with multilayer thin film flux transformers. High-Tc SQUID magnetometers are promising in various biomedical applications, including magnetoencephalography (MEG) and ultra-low field magnetic resonance imaging (ulf-MRI). LÄS MER

  7. 10. Dynamics and Applications of Long Josephson Junctions

    Författare :Yongming Zhang; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The first object of this work is to theoretically study the effects of tunnel junction parameters on flux-flow Josephson oscillators (FFOs) by numerical simulation and to experimentally study the rf properties of FFOs by integrating them together with an SIS (superconductor-insulator-superconductor) mixer/detector on a chip. By using a CAD modeled integrated sub-mm wave receiver, the composite linewidth of two FFOs was measured to be less than 2. LÄS MER