Analysis of vortex movement in an YBCO thin film: Models of the vortex solid-to-liquid transition compared to a sensitive resistive measurement of a strongly pinned YBCO thin film
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
When a high-temperature superconductor transitions in the presence of a magnetic field, the resistance does not immediately go to zero. Instead, the transition is smoothed by the resistive effects of moving vortices so that perfect conductivity isn't reached until several K below Tc, where the vortices have frozen into a glass state. The properties of this glass depend mainly on the amount and correlation between impurities in the superconductor. This report describes a study of the glass transition in an YBCO thin film rich in uncorrelated impurities. The aim was to use sensitive resistive measurements to determine which of two models of this transition, the vortex glass model and the vortex molasses model, is more accurate. After evaluation, both models are found lacking and a third model is put forth. This model, which resembles the normal distribution, excellently describes the YBCO thin film case. When the new model is tested against data from similar measurements, an YBCO single crystal and a TlBaCaCuO thin film, the results are mixed. Further study is suggested to determine the model's range of validity.
Place, publisher, year, edition, pages
2013. , 51 p.
High-temperature superconductor, YBCO, vortex dynamics, glass transition, vortex glass, vortex molasses
Other Computer and Information Science
IdentifiersURN: urn:nbn:se:kth:diva-140589OAI: oai:DiVA.org:kth-140589DiVA: diva2:691228
Master of Science - Nanotechnology
Andersson, Magnus, Universitetslektor