A two-step calcination method for preparing YBa2Cu3O7-x powders
Journal
Materials Letters
Journal Volume
7
Journal Issue
5-6
Pages
165-168
Date Issued
1988
Author(s)
Abstract
A two-step calcination method for preparing superconducting YBa2Cu3O7-x powders was developed. In this method, a single-phase BaCuO2 powder was first prepared by calcining a stoichiometric mixture of BaCO3 and CuO. After being wet-milled and sedimentation classified, the BaCuO2 powder was calcined with Y2O3 and CuO to generate the YBa2Cu3O7-x powder. At temperatures above 930°C, a single-phase YBa2Cu3O7-x powder was obtained in less than 2 h. In contrast to the conventional one-step calcination approach, the two-step calcination method completely separates the BaCO3 decomposition process, which is very slow, from the YBa2Cu3O7-x formation step. While the total time of the process for both methods is approximately the same, the calcining time for the formation of the YBa2Cu3O7-x compound in the two-step method is significantly shorter. As a result, the YBa2Cu3O7-x powders prepared via the two-step method have narrower particle size distributions, smaller particle sizes, and the sintered pellets have superior superconducting properties than those prepared via the conventional calcination method. © 1988.
Type
journal article