Sol-gel route to high T_c ceramic precursors

An aqueous sol-gel procedure to obtain fine Y-Ba-Cu particles with an approximately 1-2-3 stoichiometric ratio is described. This involves precipitating an aqueous solution of the oxides in HC1 by neutralization with Ba(OH)2, and precipitation of BaCO3 from solution with CO2. A novel treatment with H2O2 decreased the weight loss while sintering. The average particle size and shape was characterized by rheology, light scattering, and scanning electron microscope. Particle composition was studied with x-ray diffraction, electron microprobe, and infrared spectroscopy. The suspension was formed into a fiber and sintered, and measurements were made indicating a superconducting transition temperature near 60 K. © 1991, Materials Research Society. All rights reserved.