The Effect of H₂O Partial Pressure in a Calcining Atomosphere on the Critical Temperature of YBa₂Cu₃O_7-x

Abstract

The effect of water vapor in a calcining atomosphere on Tc, off of YBa₂Cu₃O_7-x was investigated using the electrical resistivity method, X-ray diffraction analysis and carbon analysis. The results are as follows:
(1) The critical temperature(To, off) elevated with increasing H₂O partial pressure, reached a maximum(90.5K) at a H₂O partial pressure of about 5kPa, and then lowered.
(2) The water vapor remarkably accelerated the decomposition of BaCO₃. However, the excessive addition of water vapor was detrimental because of the formation of an unknown phase.