Mass Spectrometric Probing of Laser-Induced Materials Vapor Transport: Graphite and Superconducting YBa2Cu3Ox

Abstract

ABSTRACTA very high pressure-sampling mass spectrometer has been used to identify the vapor transport species and determine the thermochemistry and kinetics of laser-induced plumes produced from graphite and superconducting composition YBa2Cu3Ox targets (x = 6.5 to 7). An electron impact ion source was used for the ionization and detection of neutral plume species. The plumes initially contain -1 atm (1 atm = 101.325 kPa) of neutral and charged atomic and molecular species in a vacuum of <10−7 atm. Time resolved mass spectra were obtained with graphite targets for the neutral plume species Cn (n = 1-9) for varying laser fluence, laser-surface interaction geometry, vapor plume-sampling geometry, and target surface morphology. Relatively low abundance charged species C1+, C2+, C3+, and impurities Na+ and K+ were also observed in the laser-induced plume.Mass spectra obtained with superconducting YBa2Cu3Ox targets showed a variety of species in the laser-induced plumes including both neutral and ionic Y, Ba, and Cu. In addition, molecular species such as O2, BaO, CuO+, YO and bimetallics (BaCu, YCu) were observed.