Sökning: "untwinned YBCO"

Hittade 4 avhandlingar innehållade orden untwinned YBCO.

  1. 1. On the Zero and Low Field Vortex Dynamics : An Experimental Study of Type-II Superconductors

    Författare :Örjan Festin; Peter Svedlindh; Piero Martinoli; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Engineering physics; high temperature superconductors; thermal fluctuations; YBCO; MgB2; anisotropic superconductors; vortex dynamics; Kosterlitz-Thouless transition; current voltage characteristics; complex conductivity; Flux noise; Teknisk fysik; Engineering physics; Teknisk fysik;

    Sammanfattning : Dynamic properties of type-II superconductors have been experimentally studied in zero and low magnetic fields using SQUID magnetometry and I–V measurements.In zero magnetic field close to the critical temperature, the physical properties of type-II superconductors are dominated by spontaneously created vortices. LÄS MER

  2. 2. Reshaping the phase diagram of YBa2Cu3O7-δ through strain in ultrathin films and nanowires

    Författare :Eric Wahlberg; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; High-Tc superconductors; thin-films; underdoped; nanowires; charge density wave; strange metal; YBCO; phase-slip;

    Sammanfattning : This thesis aims at adding important pieces to the puzzle of understanding the physics of the High critical Temperature Superconductor (HTS) cuprates, where despite over 30 years of intense research many open questions remain. The HTS cuprates are characterized by an incredibly complex phase diagram with multiple intertwined local orders, such as charge density waves (CDW). LÄS MER

  3. 3. Resistive studies of vortices and fluctuations in single crystal YBa2Cu3O7-

    Författare :Therese Björnängen; KTH; []
    Nyckelord :condensed matter physics; high temperature superconductors; YB2Cu3O7-d; untwinned YBCO; oxygen deficiency; superconducting fluctuations; magnetoconductivity; in-plane anisotropy; vortex liquid; vortex solid; vortex correlation;

    Sammanfattning : High-temperature superconductors have been intensely studiedsince the discovery, almost 20 years ago. Their layeredstructure, extreme type-II behavior, large anisotropy, andstrong fluctuations have led to a large number of new andinteresting problems. LÄS MER

  4. 4. YBCO nanowires to study nanoscale ordering in High-Tc Superconductors

    Författare :Riccardo Arpaia; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanoscale ordering; nanoSQUIDs; nanowires; High-Tc superconductors; ultrathin films; oxygen doping; nanowire-based single photon detectors;

    Sammanfattning : We present the realization of YBa2Cu3O7-δ (YBCO) nanowires for both basic physics studies, which could help to elucidate the microscopic mechanisms of High critical Temperature Superconductors (HTS), and for novel applications.The first part of the thesis describes an improved nanopatterning procedure, based on e-beam lithography in combination with an amorphous carbon mask and a very gentle Ar+ ion etching. LÄS MER