A mass spectrometric study on the formation of ionic Ta-containing oxides from laser ablation of Ta and Ta2O5 in O2 ambient

Formation of the ionic Ta-containing oxides in 532 nm laser ablation of Ta and Ta2O5 in an ambient O-2 is investigated using a time-of-flight mass spectrometry. Mass spectra are taken both in vacuum and in an oxygen ambient. Results of the detected positive charged species show that besides the TaO+ and TaO2+ ions, the new species such as (O-2)TaO+ and (O-2)Ta(O-2)(+) are observed for the first time. The molecular geometries of the Ta-containing ionic oxides are predicted. Along with the theoretically calculated energy changes of possible oxidation reactions involved, the reaction channels for the formation of the ionic Ta-containing oxides are discussed. (Int J Mass Spectrom 188 (1999) 205-212) (C) 1999 Elsevier Science B.V.