Premium
Preparation of 1‐2‐3 Superconductors from Hydroxide–Carbonate Coprecipitation
Author(s) -
Morgan Douglas,
Maric Milena,
Luss Dan,
Richardson James T.
Publication year - 1990
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1990.tb04257.x
Subject(s) - coprecipitation , calcination , decantation , carbonate , alkali metal , aqueous solution , hydroxide , chemistry , precipitation , potassium carbonate , inorganic chemistry , sodium carbonate , potassium hydroxide , sodium hydroxide , particle size , nuclear chemistry , materials science , mineralogy , sodium , chromatography , catalysis , organic chemistry , physics , meteorology
A batch coprecipitation of 1‐2‐3 superconductor precursor powder was accomplished by adding an aqueous solution of mixed nitrates rapidly to a mixture of sodium or potassium hydroxide and carbonate. The blue hydrogel, an intimate mixture of Y(OH) 3 , BaCO 3 , and Cu(OH) 2 , was filtered and washed by decantation, using water sparged with CO 2 to control the pH. After a second filtration, drying and calcination, the product was a homogeneous powder, with an average particle size of about 1 μm, free of alkali, and with excellent superconducting properties. The process is reproducible, inexpensive, and easy to scale to higher production rates. Important process parameters are the following: the time and temperature of precipitation; alkali ratios; volume, temperature, and pH of the wash water; and time of calcination.