SUPERCONDUCTING PROPERTIES OF TERNARY GRAPHITE INTERCALATION COMPOUNDS

by

ALISON CHAIKEN

[Note: I have only cleaned up about half the files in this tree, so there are a lot of missing links and equations.]

Submitted to the Department of Physics in December 1988 in partial
fulfillment of the requirements for the degree of Doctor of Philosophy in Physics.

• Abstract
• Acknowledgements
• Contents
• List of Figures
• List of Tables
• Introduction
• Anisotropic Superconductivity: A Brief Survey
  • Introduction
  • Upper Critical Field Studies of Artificially Structured Superlattices
  • Upper Critical Field Studies of High Temperature Superconductors
  • Discussion and Conclusions
• Sample Preparation and Characterization
  • Introduction
  • Preparation of KHg- and CsBi-GIC's
  • Normal-State Characterization of KHg- and CsBi-GIC's
    • Characterization with (00l) X-Rays
    • Raman Characterization of C4KHg
    • Neutron Diffraction Studies of C4KHg
    • Chemical Analysis of KHg- and CsBi-GIC's
    • Zero-Field Tc Measurements in C4KHg
  • Discussion and Conclusions
• Upper Critical Field Measurements on Stage I KHg--GIC's
  • Introduction
  • Experimental Methods: Hc2 Data
    • Mounting the GIC's for Critical Field Measurements
    • Data Acquisition System
    • Procedure for Obtaining Data and Data Analysis
  • Experimental Results: Angular Dependence of the Upper Critical Field
    • Extrinsic Influences on Hc2(theta) in Anisotropic Superconductors
    • Type I Superconductivity in C4KHg
    • Type II/1 Superconductivity and C4KHg
    • Tinkham's Formula Fits to Hc2(theta) in C4KHg
    • Microscopic Models of Superconductivity and Hc2(theta) in C4KHg
  • Experimental Results: Temperature Dependence of the Upper Critical Field
  • Possible Interpretations of Enhanced Linearity and Positive Curvature in GIC's
    • Dimensional Crossover Models
    • Critical Field Enhancement in Isotropic Superconductors
    • Multiband and Anisotropic Gap Models of Superconductivity
  • Discussion and Conclusions
• Hydrogenation Experiments on KHg-GIC's
  • Introduction
  • Hydrogenation and Superconductivity in Other Systems
    • Hydrogenation of the Elemental Superconductors
    • Superconductivity in the Potassium-Hydrogen GIC's
    • Hydrogenation of the Transition Metal Dichalcogenide Superconductors
  • Experimental Methods: Hydrogenation Experiments
  • Effect of Hydrogenation on Superconductivity in the KHg-GIC's
  • Possible Explanations for the Hydrogen-induced Tc Enhancement
  • Conclusions
• Experiments on CsBi-GIC's
  • Introduction
  • The Quest for Superconductivity in CsBi-GIC's
    • Experimental Method
    • Results
  • Magnetotransport Measurements on CsBi-GIC's
    • Magnetoresistance Measurements: Experimental Considerations
    • Results
  • Discussion
• Conclusions and Prospects
  • Summary of New Results
  • Conclusions
  • Suggestions for Future Research
• Estimation of the Hydrogen Debye-Waller Factor
• Effect of Tilt on Angular Dependence of the Critical Field
• Estimation of the Dimensionless ``Cleanliness'' Parameter
• References