학술논문

Thermal processing of spray-pyrolyzed and electrodeposited Tl superconductor films and optimization of the transport critical current density
Document Type
Periodical
Source
IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 5(2):1958-1961 Jun, 1995
Subject
Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Thermal spraying
Superconducting films
Critical current density
Conducting materials
Morphology
Scanning electron microscopy
Optical films
Optical microscopy
Thermal conductivity
Pressure control
Language
ISSN
1051-8223
1558-2515
2378-7074
Abstract
Employing a flow-through "two-zone" thermal processing system to control thallous oxide vapor pressure, we have investigated two different types of precursors and explored their potential for producing open tape conductors with high critical current densities. The two methods examined were: (1) precursor Pb-Sr-Ba-Ca-Cu-O(Ag) sprayed as a colloidal ink onto a heated substrate; (2) precursor material deposited by electrodeposition from an electrolytic solution containing the metal nitrates. Although both of these methods produce precursors with the proper stoichiometric ratios, vast differences in other properties such as reactivity, density, thickness, and morphology exist. The effects of these precursor properties upon subsequent superconducting characteristics such as phase development, final morphology, and electrical transport are characterized by XRD, SEM/optical microscopies, R vs. T and J/sub c/ measurements, respectively. Both types of precursors have produced superconducting films with high J/sub c/'s. Phase-pure textured films have been obtained on a variety of substrates.ETX