Sökning: "critical current density"

Visar resultat 16 - 20 av 82 avhandlingar innehållade orden critical current density.

1. 16. Key Components for High Tc SQUID Magnetometers

   Författare :Per-Åke Nilsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis describes the development of key components for superconducting quantum interference device (SQUID) magnetometers in the high temperature superconductor YBa2Cu3O7 (YBCO). Such magnetometers are made for liquid nitrogen temperature operation, as opposed to low Tc devices that are confined to liquid helium. LÄS MER

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

   Författare :Riccardo Arpaia; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

4. 18. Step Edge Junctions in YBa2Cu3O7-δ High-Tc Superconductors

   Författare :Huai-ren Yi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; YBa2Cu3O7-delta; barrier property; Josephson flux-flow transistor; laser deposition; electron-beam lithography; magnetron sputtering; thin film; step edge junction; amorphous carbon;

   Sammanfattning : This thesis describes experimental work on GdBa2Cu3O7-.delta. (GBCO) thin films, YBa2Cu3O7-.delta. LÄS MER

5. 19. Sub-micron Structures in Laser Ablated YBa2Cu3O7-x Thin Films

   Författare :Peter Larsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis treats the epitaxial growth of high-Tc superconductors and other perovskite oxides as well as the patterning of these into sub-micron structures for superconducting electronic devices. A computer controlled laser ablation system, based on a KrF excimer laser (248 nm) to induce ablation, was developed to allow complex thin film growth processes. LÄS MER

7. 20. Silicon Carbide Technology for High- and Ultra-High-Voltage Bipolar Junction Transistors and PiN Diodes

   Författare :Arash Salemi; Mikael Östling; Carl-Mikael Zetterling; Anders Hallen; Nando Kaminski; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Informations- och kommunikationsteknik; Information and Communication Technology;

   Sammanfattning : Silicon carbide (SiC) is an attractive material for high-voltage and high-temperature electronic applications owing to the wide bandgap, high critical electric field, and high thermal conductivity. High- and ultra-high-voltage silicon carbide bipolar devices, such as bipolar junction transistors (BJTs) and PiN diodes, have the advantage of a low ON-resistance due to conductivity modulation compared to unipolar devices. LÄS MER