Accession Number : ADP007470

Title :   Control of YBA2CU3OY Sol-Gel Solution Structure by Chemical Modification of Organic Acid and its Effects,

Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND MINERAL ENGINEERING

Personal Author(s) : Zheng, Haixing ; Mackenzie, J.D.

Report Date : FEB 1991

Pagination or Media Count : 6

Abstract : Since the discovery of the high temperature superconducting ceramics, numerous techniques have been tested in order to overcome the difficulties in the fabrication (e.g. porosity, preparation of specific shapes). The sol-gel process has been demonstrated to be ideal for the fabrication of high Tc superconducting ceramic fibers or wires (1). In the sol-gel process, the metal alkoxides in organic solvents are hydrolysized and polymerized (2). These low temperature solution reactions yield the ultrahomogeneity of materials and low final phase-forming and densification temperature (3). By controlling the hydrolysis and polycondensation reactions a homogeneous solution with proper viscosity can be made for the fiber drawing and film coating (4). Water content, modification of sol-gel solution are two common techniques to control a solution reaction 1,5. Here we have studied the structure change induced by the modification of the metal alkoxide solution by 2EHA. Further effects of 2EHA on the formation of YBa2CU307-x, microstructure and superconductivity of final products have been investigated.

Descriptors :   *MICROSTRUCTURE, CERAMIC FIBERS, COATINGS, CONTROL, FABRICATION, FIBERS, FILMS, GELS, HIGH TEMPERATURE, HYDROLYSIS, LOW TEMPERATURE, MATERIALS, METALS, MODIFICATION, ORGANIC SOLVENTS, POROSITY, PREPARATION, SOLVENTS, STRUCTURES, SUPERCONDUCTIVITY, TEMPERATURE, VISCOSITY, WATER, WIRE, YIELD.

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE