Laser ablation of YBa₂Cu₃O7-δ as probed by laser-induced fluorescence spectroscopy

Ground-state populations of cationic and neutral Y, Ba, Cu, and neutral YO, BaO, and CuO are monitored by laser-induced fluorescence during laser ablation of YBa₂{Cu}₃O_7-δ. 193-nm photons completely dissociate CuO allowing the observation of a subsequent reaction of the Cu atom with O₂ to form CuO. As a function of O₂ pressure, the CuO signal increases to a maximum at approximately 120 mTorr of O₂, presumably minimizing {δ}, and then falls to negligible levels by 400 mTorr. Ablation at 248 and 351 nm dissociates a smaller fraction of the CuO, i.e., nascent CuO is observed in the absence of O₂.