Laser ablation of bulk YBa2Cu3O7−δ and cluster emission

Abstract

Mass spectral investigations of ions produced directly from 1064‐nm plus 532‐nm laser beam ablation of a bulk high‐T_c superconducting YBa₂Cu₃O_7−δ target reveal significant cluster emission as well as very intense low‐mass emission up to but below laser beam energy densities required to visually observe a plume of white light; at higher laser intensities, cluster emission essentially disappears while low‐mass ion intensities continue to grow. Cluster mass patterns ranging above 10⁴ amu are observed and believed to be products of condensation rather than direct emission. Cluster ions higher in mass although not in distinguishable patterns, ranging beyond 10⁶ amu, are observed, possibly due to direct emission. These results are relevant to high‐T_c superconducting thin‐film deposition by the laser ablation technique.