LBNL Report Number
Thin films of Y‐Ba‐Cu‐O were deposited by rf magnetron sputtering from a single stoichiometric target and then altered in composition by ion implantation. Under optimum deposition conditions the films are deficient in Ba and Cu. Ion implantation of Cu was performed using a metal‐vapor vacuum‐arc source having high current and a broad energy spectrum for good depth distribution. Composition was determined by Rutherford backscattering spectrometry. The zero‐resistance temperature was greatly increased after implantation and reannealing. This method could be used to write superconducting patterns on insulating material.