Plasma oxidation of Ba2YCu3O7−y thin films

Abstract
We studied the effects of plasma oxidation on the electrical properties of Ba2YCu3O7y thin films. Films were prepared by electron beam evaporation, then annealed in oxygen. Plasma oxidation, performed in a barrel reactor, lowered the room‐temperature resistivity of films and raised the zero‐resistance temperature. Film resistivity increased a few percent a day after plasma oxidation. The rate of resistivity increase is several times that of untreated samples. Changes in resistivity and critical temperature could be completely reversed by repeated plasma treatment.