Study of Transport and Mechanical Properties of YBCO Composite Superconductor

Abstract

The thesis work mainly ascribes the modification on the structural, electric &magnetic transport, and mechanical properties of pristine YBa2Cu3O7−δ superconductor and its composites with carbon-based compound (carbon nanotubes and graphene oxide), manganites, and ferrites. These materials were synthesized by the solid-state reaction route. The modified physical and chemical properties of the materials have been discussed through a weak-link mechanism, order parameter fluctuation, developments of artificial pinning centres, inhomogeneities. Various models are also introduced to verify the experimental data to explore meaningful observations. The above mentioned work has been discussed thoroughly in six different chapters as follows: Chapter 01 gives a brief introduction to superconductors with various phenomena, novel superconducting theories, and their classifications. Moreover, clear descriptions regarding the motivation and objective of the whole thesis work have been presented. Chapter 02 presents a detailed description of the synthesis techniques adopted for the preparation of the pristine as well as composite superconductors followed by the experimental techniques. The experimental techniques are used for the characterization of structural, transport, magnetic and mechanical properties of the pristine and its composite materials. Chapter 03 has two parts. Part 01 describes the structural modifications and variation of properties of YBCO superconductor with the addition of various wt. % of carbon nanotubes (CNTs). Part 02 deals with the effect of CNTs addition on the structural and mechanical properties of YBCO synthesized material. Chapter 04 describes the variation of structural, transport and mechanical properties of (1-x) YBa2Cu3O7-δ + x Graphene Oxide (GO) composite system. Chapter 05 has two parts. Part 01 deals with the variations of superconducting and mechanical properties of YBa2Cu3O7-δ composite thick films with La0.67Sr0.33MnO3 (LSMO). Part 02 describes the variation superconducting parameters along with excess conductivity analysis of CoFe2O4 added YBCO samples. Chapter 06 gives the summary of the thesis work with future scope. The work outlined in the present thesis has been published in international journals.