Laser ablation of bulk target in liquid allows to obtain stable nanoparticles and nanostructures,... more Laser ablation of bulk target in liquid allows to obtain stable nanoparticles and nanostructures, also in metastable phases, limiting the use of hazardous reagents and extreme reaction conditions. Titanium carbide (TiC) is a ceramic compound with several technological applications ranging from biocompatible materials to wear resistant coatings. The possibility to obtain core/shell structures expands its range of application due to the ability of modify the surface properties of the core ceramic material. TiC and metallic titanium targets have been ablated by means of an ultra-short laser source in different liquid media (water, acetone, n-hexane and toluene). The obtained colloidal solutions have been characterized by TEM, XRD and micro-Raman analysis. In all the used experimental conditions TiC nanoparticles have been produced. During water and acetone mediated ablations, the oxidation of titanium has been observed, whereas by using oxygen free solvents, such as n-hexane and toluene, core/shell TiC nanoparticles embedded in amorphous and graphitic carbon shell, respectively, have been obtained.
A theoretical model of laser ablation has been previously developed and applied to Laser Induced ... more A theoretical model of laser ablation has been previously developed and applied to Laser Induced Breakdown Spectroscopy (LIBS) analysis of bronzes with the aim to improve quantitative results and to focus on problems arising in the interpretation of experimental data. The model describes laser-solid matter interaction, plume expansion, plasma formation and laser-plasma interaction. A two temperature approach has been also introduced to take into account the initial temperature dynamics of the alloy surface upon ultra-short laser irradiation. We examined various target compositions, typical of archaeological artworks, and different laser characteristics such as wavelength (355 nm, 530 nm, 1064 nm) and pulse duration (8 ns, 250 fs). In this work, the model has been extended to simulate double pulse LIBS configuration in order to clarify the mechanism involved in the process and for better interpreting the experimental data. Plasma composition, relevant parameters (temperature, electron density) and their kinetic evolutions have been measured. Results have been compared with the simulation obtained using the same irradiation conditions and set of targets.
ABSTRACT Pulsed laser ablation has been applied to thin films deposition from a tin selenide targ... more ABSTRACT Pulsed laser ablation has been applied to thin films deposition from a tin selenide target. The growth of SnSe films has been analysed by electrical and optical techniques. The effect of laser fluence on the properties of the deposits has been also studied.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2014
ABSTRACT Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certifi... more ABSTRACT Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certified copper alloys and relative calibration plots of a fs-ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration is presented. All work was performed in air at atmospheric pressure using certified copper-based-alloy samples irradiated by a fs laser beam and followed by a delayed perpendicular ns laser pulse. In order to evaluate possible compositional changes of the fs induced nanoparticles, it was necessary to consider, for all samples used, comparable features of the detected species. With this purpose the induced nanoparticles black-body-like emission evolution and their relative temperature decay have been studied. These data were exploited for defining the distance between the target surface and the successive ns laser beam to be used. The consequent calibration plots of minor constituents (i.e. Sn, Pb and Zn) of the certified copper-based-alloy samples have been reported by taking into account self-absorption effects. The resulting linear regression coefficients suggest that the method used, for monitoring and ruling the fs laser induced nanoparticles, could provide a valuable approach for establishing the occurrence of potential compositional changes of the detected species. All experimental data reveal that the fs laser induced nanoparticles can be used for providing a coherent composition of the starting target. In the meantime, the fs-ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration here used can be considered as an efficient technique for compositional determination of the nanoparticles ejected during ultra-short laser ablation processes.
... Induced Breakdown Spectroscopy for semi-quantitative and quantitative analyses of artworks ... more ... Induced Breakdown Spectroscopy for semi-quantitative and quantitative analyses of artworks ap-plication on multi-layered ceramics and copper based alloys, Spectrochim Acta B 57 (2002) 12191234 4. A. Ciucci, V. Palleschi, S. Rastelli, A. Salvetti, and E. Rognoni, A new ...
... Tita Scala, Italy 1. Introduction Carbides of the group 4 elements are refractory materials w... more ... Tita Scala, Italy 1. Introduction Carbides of the group 4 elements are refractory materials widely used as coatings in the high ... [2] PK Ashwini, V. Kumar and J. Sarkar,./. ... [4] L. D'Alessio, A. Santagala, R. Teghil, M. Zaccagnino, I. Zaccardo, V. Marotta, D. Ferto and G. De Maria, Appl. ...
ABSTRACT The pulsed laser ablation and deposition of Sr2FeMoO6 films having good magnetic perform... more ABSTRACT The pulsed laser ablation and deposition of Sr2FeMoO6 films having good magnetic performances is strongly affected by the adopted deposition parameters, which require precise choices. Among them, the laser energy density seems to be the basic factor governing the achievement of the correct material phase during film growth. Optical emission spectroscopy of the plasma plume, produced by the laser interaction with stoichiometric targets, in different ablation and ambient conditions, can outline the plasma dynamics and consequently sustain hypothesis about the film formation mechanism. In order to follow the plasma dynamics during Nd:Yag laser (2=532 nm) ablation of Sr2FeMoO6 targets, time- and space-resolved optical emission spectroscopy measurements in the range 350 -500 nm have been performed. The integral intensities of spectral lines were measured as a function of distance from the target surface and laser power density in the presence of 02 partial pressure. The intensity ratio of ionic and atomic Strontium emission spectral line and their time-of-flights were measured as a function of laser energy density. On the basis of the obtained results it is shown how different plasma species kinetics can play a key role in determining the magnetic film properties.
Laser ablation of bulk target in liquid allows to obtain stable nanoparticles and nanostructures,... more Laser ablation of bulk target in liquid allows to obtain stable nanoparticles and nanostructures, also in metastable phases, limiting the use of hazardous reagents and extreme reaction conditions. Titanium carbide (TiC) is a ceramic compound with several technological applications ranging from biocompatible materials to wear resistant coatings. The possibility to obtain core/shell structures expands its range of application due to the ability of modify the surface properties of the core ceramic material. TiC and metallic titanium targets have been ablated by means of an ultra-short laser source in different liquid media (water, acetone, n-hexane and toluene). The obtained colloidal solutions have been characterized by TEM, XRD and micro-Raman analysis. In all the used experimental conditions TiC nanoparticles have been produced. During water and acetone mediated ablations, the oxidation of titanium has been observed, whereas by using oxygen free solvents, such as n-hexane and toluene, core/shell TiC nanoparticles embedded in amorphous and graphitic carbon shell, respectively, have been obtained.
A theoretical model of laser ablation has been previously developed and applied to Laser Induced ... more A theoretical model of laser ablation has been previously developed and applied to Laser Induced Breakdown Spectroscopy (LIBS) analysis of bronzes with the aim to improve quantitative results and to focus on problems arising in the interpretation of experimental data. The model describes laser-solid matter interaction, plume expansion, plasma formation and laser-plasma interaction. A two temperature approach has been also introduced to take into account the initial temperature dynamics of the alloy surface upon ultra-short laser irradiation. We examined various target compositions, typical of archaeological artworks, and different laser characteristics such as wavelength (355 nm, 530 nm, 1064 nm) and pulse duration (8 ns, 250 fs). In this work, the model has been extended to simulate double pulse LIBS configuration in order to clarify the mechanism involved in the process and for better interpreting the experimental data. Plasma composition, relevant parameters (temperature, electron density) and their kinetic evolutions have been measured. Results have been compared with the simulation obtained using the same irradiation conditions and set of targets.
ABSTRACT Pulsed laser ablation has been applied to thin films deposition from a tin selenide targ... more ABSTRACT Pulsed laser ablation has been applied to thin films deposition from a tin selenide target. The growth of SnSe films has been analysed by electrical and optical techniques. The effect of laser fluence on the properties of the deposits has been also studied.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2014
ABSTRACT Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certifi... more ABSTRACT Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certified copper alloys and relative calibration plots of a fs-ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration is presented. All work was performed in air at atmospheric pressure using certified copper-based-alloy samples irradiated by a fs laser beam and followed by a delayed perpendicular ns laser pulse. In order to evaluate possible compositional changes of the fs induced nanoparticles, it was necessary to consider, for all samples used, comparable features of the detected species. With this purpose the induced nanoparticles black-body-like emission evolution and their relative temperature decay have been studied. These data were exploited for defining the distance between the target surface and the successive ns laser beam to be used. The consequent calibration plots of minor constituents (i.e. Sn, Pb and Zn) of the certified copper-based-alloy samples have been reported by taking into account self-absorption effects. The resulting linear regression coefficients suggest that the method used, for monitoring and ruling the fs laser induced nanoparticles, could provide a valuable approach for establishing the occurrence of potential compositional changes of the detected species. All experimental data reveal that the fs laser induced nanoparticles can be used for providing a coherent composition of the starting target. In the meantime, the fs-ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration here used can be considered as an efficient technique for compositional determination of the nanoparticles ejected during ultra-short laser ablation processes.
... Induced Breakdown Spectroscopy for semi-quantitative and quantitative analyses of artworks ... more ... Induced Breakdown Spectroscopy for semi-quantitative and quantitative analyses of artworks ap-plication on multi-layered ceramics and copper based alloys, Spectrochim Acta B 57 (2002) 12191234 4. A. Ciucci, V. Palleschi, S. Rastelli, A. Salvetti, and E. Rognoni, A new ...
... Tita Scala, Italy 1. Introduction Carbides of the group 4 elements are refractory materials w... more ... Tita Scala, Italy 1. Introduction Carbides of the group 4 elements are refractory materials widely used as coatings in the high ... [2] PK Ashwini, V. Kumar and J. Sarkar,./. ... [4] L. D'Alessio, A. Santagala, R. Teghil, M. Zaccagnino, I. Zaccardo, V. Marotta, D. Ferto and G. De Maria, Appl. ...
ABSTRACT The pulsed laser ablation and deposition of Sr2FeMoO6 films having good magnetic perform... more ABSTRACT The pulsed laser ablation and deposition of Sr2FeMoO6 films having good magnetic performances is strongly affected by the adopted deposition parameters, which require precise choices. Among them, the laser energy density seems to be the basic factor governing the achievement of the correct material phase during film growth. Optical emission spectroscopy of the plasma plume, produced by the laser interaction with stoichiometric targets, in different ablation and ambient conditions, can outline the plasma dynamics and consequently sustain hypothesis about the film formation mechanism. In order to follow the plasma dynamics during Nd:Yag laser (2=532 nm) ablation of Sr2FeMoO6 targets, time- and space-resolved optical emission spectroscopy measurements in the range 350 -500 nm have been performed. The integral intensities of spectral lines were measured as a function of distance from the target surface and laser power density in the presence of 02 partial pressure. The intensity ratio of ionic and atomic Strontium emission spectral line and their time-of-flights were measured as a function of laser energy density. On the basis of the obtained results it is shown how different plasma species kinetics can play a key role in determining the magnetic film properties.
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