Anomalous compositional dependence in in situ growth of YBaCuO films at low oxygen pressure

Abstract
The roles of composition and oxygen pressure in in situ growth of superconducting YBaCuO films have been studied. Anomalous results are observed at low oxygen pressure. Off‐stoichiometric, Ba‐deficient films have superior superconducting properties and more bulk‐like crystal structure compared to films made on the 1:2:3 stoichiometry. Films made at low pressure have an expanded c axis compared to the bulk value, although their Tc’s are only slightly depressed. Tc and c‐axis lattice parameters are reported as a function of the deposition conditions.