As-Deposited Superconducting Ba₂YCu₃O_7-y Films Using ECR Ion Beam Oxidation

Abstract

Superconducting Ba 2 YCu 3 O 7- y films have been grown epitaxially on (100) and (110) SrTiO 3 substrates at a substrate temperature of 600°C using an evaporator combined with an ECR ion source for oxidation. Three molecular beams (BaF 2 , Y and Cu) were deposited simultaneously under the oxygen ion-beam (50 eV) bombardment. The as-deposited films showed zero resistance at 80–82 K with thicknesses between 200 and 700 nm on both (100) and (110) substrates. The oxygen ion beam was very useful to oxidize the metal sufficiently, to dissociate the BaF 2 molecules and to lower the substrate temperature.