Laser ablation of bulk YBa2Cu3O7−δ and cluster emission

Mass spectral investigations of ions produced directly from 1064-nm plus 532-nm laser beam ablation of a bulk high-Tc superconducting YBa2Cu3O7−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-Tc superconducting thin-film deposition by the laser ablation technique.