University of Kentucky UKnowledge Theses and Dissertations--Physics and Astronomy Physics and Astronomy 2012 MAGNETIC PROPERTIES OF Nb/Ni SUPERCONDUCTING / FERROMAGNETIC MULTILAYERS Sergiy A. Kryukov University of Kentucky, kryukoff@gmail.com Click here to let us know how access to this document benefits you. Recommended Citation Kryukov, Sergiy A., "MAGNETIC PROPERTIES OF Nb/Ni SUPERCONDUCTING / FERROMAGNETIC MULTILAYERS" (2012). Theses and Dissertations--Physics and Astronomy. 7. https://uknowledge.uky.edu/physastron_etds/7 This Doctoral Dissertation is brought to you for free and open access by the Physics and Astronomy at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Physics and Astronomy by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu.
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TABLE OF CONTENTS ACKNOWLEDGEMENTS.........III LIST OF FIGURES... IV LIST OF TABLES...VI CHAPTER ONE - INTRODUCTION... 1 1.1. Background for Superconductivity... 1 1.1.1. Discovery... 1 1.1.2. Meissner Effect and London theory.... 1 1.1.3. Type I/II Superconductors, Quantized Vortices... 6 1.1.4. Mixed Phase or Abrikosov Vortex State... 13 1.1.5. Microscopic BCS Theory... 15 1.2. Ferromagnetism.... 20 1.2.1. Finite Size Effects on Ferromagnetic Ordering... 23 1.3. The Proximity Effect... 25 1.3.1. Superconductor Normal-Metal Structures...25 1.3.2. Superconductor-Ferromagnet Structures...30 1.3.2.1 Superconductor-Ferromagnet Structures with Uniform Magnetization...38 1.3.2.2.Density of States...41 1.3.2.3.Transition Temperature Nonmonotonic Variations...44 1.3.3. The Josephson Effect in S/F/S Junctions...48 CHAPTER TWO - EXPERIMENTAL TECHNIQUES AND RESEARCH TOOLS...51 2.1. SQUID Magnetometer... 51 2.1.1. AC Measurements... 51 2.1.2. DC Measurements... 52 2.1.3. SQUID RSO Option... 53 2.2. Vibrating Reed Technique... 56 2.3. Transmission Electron Microscopy... 58 2.4. Polarized Neutron Reflectometry... 58 CHAPTER THREE - EXPERIMENTAL RESULTS... 59 3.1. Nb/Ni Multilayers... 59 iv
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