Vortex dynamics in superconductors in the presence of anisotropic pinning [Elektronische Ressource] / von Oleksiy K. Soroka

Vortex dynamics in superconductors inthe presence of anisotropic pinningDissertationzur Erlangung des GradesDoktor der Naturwissenschaften (Dr.rer.nat.)am Fachbereich Physikder Johannes Gutenberg-Universit¨ at MainzvonOleksiy K. Sorokageb.in Kremenec’(Ukraine)Mainz, 2004Tag der Einreichung: 08.11.2004Tag der mundlic¨ hen Prufung:¨ 15.03.2005Vortex dynamics in superconductors inthe presence of anisotropic pinningPh. D. thesisbyOleksiy K. SorokaMainz, 2004Contents1 Basic concepts of superconductivity 11.1 Type II superconductors, vortices . . . ............... 31.2 Fluxpinningandcreep............. 61.3 High-temperature superconductors . ..... 82Guidedvortexmotion,theory 112.1 Introduction.............................. 12.2 TheFokker-Plankmethod........... 152.3 Nonlinear conductivity and resistivity tensors ........... 202.4 Calculationsusingmodelpotential ................. 22.5 Probability function and the averagepinningforce .................. 302.6 Additionalpoint-likepinning..................... 312.7 Conclusions........ 343 Guiding in YBCO 373.1 Twin formation in YBa Cu O .................. 372 3 7−δ3.2 FilmpreparationandX-rayanalysis ..... 423.3 Magnetoresistivitymeasurements....... 494 Guiding in faceted Nb-films 55¯4.1 Faceting of the Al O {1010}surface................ 52 3iii CONTENTS4.2 Samplepreparation.......................... 564.3 MagnetoresistivitymeasurementsI ...... 594.4 MagnetoresistivitymeasurementsI......