Publication Date
2006
Document Type
Thesis
Committee Members
Sharmila Mukhopadhyay (Advisor)
Degree Name
Master of Science in Engineering (MSEgr)
Abstract
This thesis reports the development of a new approach for the fabrication of superconducting thin films. Among the liquid phase methods of fabricating high temperature superconductors having critical current density about 1 MA/cm2, metalorganic deposition using metal trifluoroacetates (TFA-MOD) is the best known method. In this project, detailed spectroscopic and microscopic analysis was performed at every stage of the TFA-MOD process to understand the evolution of crystalline superconducting film. It was observed that the TFA-MOD has some inherent disadvantages such as long process time, evolution of HF gas and results porosity in films. A new liquid phase process was developed to fabricate superconducting YBCO thin films, which has the potential to overcome the above mentioned drawbacks. This process involves using a precursor, which is a colloidal suspension of Y-Ba-Cu-O nanoparticles of size ~ 20 nm. Precursor films were deposited on LaAlO3 by spin coating or dip coating and heat treated in two stage annealing process to obtain final films. Compared to MOD-TFA processed films, the nanoparticle processed films showed lower porosity and can be grown at faster heating rates. The superconducting transition temperature of nanoparticle processed YBCO films to date is ~ 89 K at R=0. Self-field critical current densities (Jc) of 2 MA/cm2 at 77 K have been achieved.
Page Count
104
Department or Program
Department of Mechanical and Materials Engineering
Year Degree Awarded
2006
Copyright
Copyright 2006, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.
