Effect of target composition on the emission enhancement observed in Double-Pulse Laser-Induced Breakdown Spectroscopy
Autori: Cristoforetti G., Legnaioli S., Palleschi V., Salvetti A., Tognoni E.
Affiliazione autori: Applied Laser Spectroscopy Laboratory, Institute for Chemical–Physical Processes Research Area of National Research Council, Via G. Moruzzi, 1, 56124 Pisa, Italy
Abstract: The effect of the matrix composition on the emission enhancement observed in Double-Pulse (DP) Laser-Induced Breakdown Spectroscopy (LIBS) was studied for several pure metal targets (Al, Au, Co, Cu, Fe, Mn, Mo, Ni, Pb, Pt, Si and W). The measurements were performed in air by using a dual-pulse Nd:YAG ns laser emitting 60mJ pulses at 1064nm wavelength. The measurement of the emission enhancement for neutral and ionic lines of all the samples showed a wide range of results. Very low enhancement was observed in Pb, Ni and Mn while the highest values of enhancement were obtained in Cu, Al and Au. The space-averaged thermodynamic parameters of the induced plasmas in DP and in SP LIBS were calculated and the enhancement of ablated atomized mass in DP case was spectroscopically estimated in all the targets. A correlation seems to exist between the ablated atomized mass enhancement and the plasma temperature increase in the DP configuration. An attempt was made to correlate the increase of these two quantities with the melting point and heat, boiling point and heat, reflectivity and ionization energy of the metal. No evident correlation was found. At the opposite, a correlation was observed between the ablated atomized mass enhancement and the thermal diffusivity of the metal. A simple picture is proposed to explain the experimental findings. It is hypothesized that different mass ablation mechanisms prevail depending on the experimental configuration. It may be expected that in the SP case mass ablation is dominated by vaporization, while in the DP case it is dominated by phase explosion and/or melt expulsion.
Giornale/Rivista: SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
Volume: 63 (2) Da Pagina: 312 A: 323
Parole chiavi: Double-Pulse; Laser-Induced Breakdown Spectroscopy; Matrix composition; MetalDOI: 10.1016/j.sab.2007.11.006Citazioni: 63dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2023-05-28Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui