Time-of-flight mass spectroscopic studies of positive ionic species generated by laser ablation of silicon carbide

Positive ionic species produced by laser ablation of silicon carbide were studied by time-of-flight (TOF) mass spectrometry. With low laser fluences, binary clusters SinCm+ (n=1–3; m=1–2) were observed in the 1064, 532 and 355 nm ablation, whereas no silicon carbide clusters were observed in the 266 nm ablation. Ablation of silicon carbide in nitrogen buffer gas was also studied by the standard cluster-beam technique. Formation of silicon–nitrogen binary clusters was readily observed, but the amounts of silicon carbide clusters were much smaller than those without the buffer gas.