Laser ablation dynamics of YBa2Cu3O7-x in an oxygen jet

Mass spectroscopic studies on a reactive laser ablation of YBa2Cu3O7-x at 266 and 1064 nm in a pulsed oxygen jet have been performed by direct sampling of ions escaping from a laser-induced plasma (plume). Energetics of the ions is studied by using a time-of-flight (TOF) quadrupole mass spectroscopy. TOF spectra of metal ions consist of a fast and a slow component, but TOF spectra of metal oxide ions show single broad distributions. Significant changes in the relative enrichment of metal oxide and oxygen ions and their TOF distributions are observed by adding oxygen molecules to the plume. Formation mechanisms of each ion are investigated by analyzing the TOF spectra with O-2 pulse on and off. The dependences of the TOF spectra on the laser wavelengths and their fluences are also examined to elucidate the acceleration mechanisms of ions as well as photochemical phenomena in the plume. (C) 1999 American Institute of Physics. [S0021-8979(99)07524-6].