In previous works it was found that sediments from the Huelva estuary (SW of Spain) are contamina... more In previous works it was found that sediments from the Huelva estuary (SW of Spain) are contaminated due to some mining and industrial activities that are concerned with the extraction of pyrites and the production of fertilizers. In the present study we have evaluated the evolution of this estuarine contamination during the last two centuries, when the most relevant episodes of the activities mentioned have occurred. To this end we collected a sediment core in the Huelva estuary, which was dated applying radiometric techniques. Some layers of this core were analysed by TTPIXE. The obtained elemental profiles correlate with the temporal evolution of the mining activities during the last 150 years, and also reflect the impact of the industrial activities since the 1960s. Additionally, the contamination in P (due only to the industrial activities), S, Fe, Cu, Zn, As and Pb was extracted and evaluated.
Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to p... more Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to provide compositional and spatial information that are typically obtained using standard micro-invasive and/or micro-destructive techniques (e.g., SEM-EDX), without the need of sampling. In this work, the specifics of the new CXRF device named μXRF-CONCHA from the Centro Nacional de Aceleradores of the University of Seville will be presented. The development of this equipment is intended to the study in situ of paintings in order to obtain depth profiles of pictorial layers by a no-destructive way. This investigation consists in studying the viability of this device for the study of pictorial layers of old paintings. The challenge consists in determining if the results obtained allow distinguishing the sequence of the paint layer and their composition. Several experimental paint multilayers have been analyzed to evaluate this setup. This paper shows that μXRF-CONCHA will be able to provide important information in order to understand and interpret the choice, palette, and technique of painters from the past.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015
ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either inte... more ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either intentional or fortuitous. When this happens, non-destructive techniques like PIXE (Proton Induced X-ray Emission) and XRF (X-Ray Fluorescence) are not sufficient to access the whole bulk pieces because their penetration depths are typically of a few tens microns. If the archeological pieces cannot be cut or polished, it is necessary to apply other non-destructive techniques to access the bulk pieces. That way, archeological bronze pieces have been successfully studied combining XRF (or PIXE) with GRT (Gamma-Ray Transmission).
6H-SiC single crystalline substrates were implanted at room temperature with 2 MeV Al2+ ions to f... more 6H-SiC single crystalline substrates were implanted at room temperature with 2 MeV Al2+ ions to fluences from 2×1014 Al2+ cm-2 to 7×1014 Al2+ cm-2 and with different current densities (from 6.6 to 33×1010 Al2+ cm-2 s-1). The depth profile of the damage induced by the Al2+ ions was determined by Backscattering Spectrometry in channeling geometry (BS/C) with a 3.5 MeV He2+ beam. The BS/C spectra were evaluated using the RBX code. The samples were subsequently annealed at 1100°C in N2 for one hour, in order to analyze their structural recovery by BS/C and the amount of the remaining defects by means of Electron Paramagnetic Resonance (EPR). The results from the BS/C spectra corresponding to the as-implanted samples indicate that the damage depends strongly on the total fluence but also, although to a lesser extent, on the beam current density. The BS/C measurements reveal that all the samples, except the one implanted with the highest fluence, recover completely their original crystall...
Improûement of the high temperature oxidation behaûior of conûentional EN-1.4301 (AISI type 304) ... more Improûement of the high temperature oxidation behaûior of conûentional EN-1.4301 (AISI type 304) stainless steel was achieûed by implanting cerium ions. Implantation was performed in samples with two different surface treatments: commercial 2B mill finishing and preoxidation in synthetic air. One set of samples was annealed after implantation in order to recoûer the damage induced in the crystalline structure. Results show that the implantation of Ce greatly improûes the oxidation resistance at 1173 K of the EN-1.4301 grade stainless steels and that the annealing treatment after the implantation is beneficial during the subsequent oxidation. Experiments confirm the presence of spinel-type compounds and Cr 2 O 3 and Fe-Cr mixed oxides with high Cr content in the scale, and martensite being the dominating metallic phase. Chromium depletion in the near-surface layers is also described. Results are compared to preûiously published data on surface modification using La and Ce by pyrolysis of aerosols.
Improvement of the high temperature oxidation behavior of conventional EN-1.4301 (AISI type 304) ... more Improvement of the high temperature oxidation behavior of conventional EN-1.4301 (AISI type 304) stainless steel was achieved by implanting cerium ions. Implantation was performed in samples with two different surface treatments: commercial 2B mill finishing and preoxidation in synthetic air. One set of samples was annealed after implantation in order to recover the damage induced in the crystalline structure. Results
Bioactive glasses of different composition were ablated in vacuum with an ArF laser to investigat... more Bioactive glasses of different composition were ablated in vacuum with an ArF laser to investigate the transfer of the multi-component system to titanium substrates. Both the bioactive coatings and the bulk glasses were analysed by Rutherford backscattering spectrometry (RBS), particle induced X-ray emission (PIXE), nuclear reaction analysis (NRA), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopies (XPS). The composition analyses
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2008
In February 1998, almost 10 years ago, the setup of the first IBA (ion beam analysis) facility in... more In February 1998, almost 10 years ago, the setup of the first IBA (ion beam analysis) facility in Spain took place with the arrival of a 3 MV tandem accelerator [
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2011
... Red layered medieval stained glass window characterization by means of micro-PIXE technique. ... more ... Red layered medieval stained glass window characterization by means of micro-PIXE technique. ... of the hot fluid glass mixture could have been separated during the manufacturing process in order to produce a red glass mixture by adding a specific raw material that provided ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1995
... collected were bombarded with 2.5 MeV protons from the 3 MV Van de Graaff accelerator in the ... more ... collected were bombarded with 2.5 MeV protons from the 3 MV Van de Graaff accelerator in the ITN at Sacavèm (Portugal), and 20 ... 477-481 Beam Interactions with Materials & Atoms Environmental impact of fertilizer industries evaluated by PIXE JE Martin a, JP Bolivar b, MA ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997
Lanthanum ions of 100 keV have been implanted in AISI304 specimens at different doses. The erosio... more Lanthanum ions of 100 keV have been implanted in AISI304 specimens at different doses. The erosion or sputtering of the surface atoms, either from the steel matrix or already implanted, during the implantation process imposes a limitation on the maximum implantable dose. Hoping to increase this dose, we deposited thin layers of aluminium and alumina (Al,Os) on top of steel samples of similar composition and sputtering behaviour (AISI302). as the sputtering effect is much weaker on such species and this layer could also prevent the steel atoms from being removed from the surface. The experimental determination of the sputtering coefficients, total or partial, and its comparison with theoretical values, when possible, is another aim of this work.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1998
The evidence of the modi®cation of the surface structure of the AISI-304 stainless steel during t... more The evidence of the modi®cation of the surface structure of the AISI-304 stainless steel during the implantation of lanthanum makes the analysis of the sputtered elements very interesting. Those sputtered elements are deposited on a carbon sheet placed in front of the steel being implanted, and studied by means of RBS and PIXE, together with the implanted specimens. Besides, the protective eect of the implanted ions during the high temperature oxidation is also studied by those techniques together with XRD and thermogravimetric methods. Ó 1998 Elsevier Science B.V.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The recently created Centro Nacional de Aceleradores (National Center for Accelerators, CNA) in S... more The recently created Centro Nacional de Aceleradores (National Center for Accelerators, CNA) in Seville emerges as the ®rst ion beam analysis facility in Spain. The laboratory is based on a 3 MV tandem accelerator model 9SDH-2 of NEC and it is primarily focused on material research and modi®cation by means of IBA techniques: PIXE, RBS, NRA, PIGME and ERDA. The ions are delivered by two ion sources: Alphatross radio-frequency source and SNICS-II sputtering source. The ion beam handling system includes equipment for beam focusing, steering and diagnosis, a 90°a nalyzing magnet and a seven-port switcher magnet. A system based on magnetic steerers has been installed for highprecision beam energy scanning. In this paper the main elements of the laboratory will be described, focusing on the electronic equipment, detectors and the four beamlines planned for the moment: channeling line, microbeam line, multipurpose vacuum chamber and external microbeam. Moreover, the characteristics of the system as observed until now by means of performance tests, beam energy spread measurements and energy calibration experiments will be summarized.
In previous works it was found that sediments from the Huelva estuary (SW of Spain) are contamina... more In previous works it was found that sediments from the Huelva estuary (SW of Spain) are contaminated due to some mining and industrial activities that are concerned with the extraction of pyrites and the production of fertilizers. In the present study we have evaluated the evolution of this estuarine contamination during the last two centuries, when the most relevant episodes of the activities mentioned have occurred. To this end we collected a sediment core in the Huelva estuary, which was dated applying radiometric techniques. Some layers of this core were analysed by TTPIXE. The obtained elemental profiles correlate with the temporal evolution of the mining activities during the last 150 years, and also reflect the impact of the industrial activities since the 1960s. Additionally, the contamination in P (due only to the industrial activities), S, Fe, Cu, Zn, As and Pb was extracted and evaluated.
Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to p... more Confocal micro X-ray fluorescence (CXRF) is gaining considerable interest due to its ability to provide compositional and spatial information that are typically obtained using standard micro-invasive and/or micro-destructive techniques (e.g., SEM-EDX), without the need of sampling. In this work, the specifics of the new CXRF device named μXRF-CONCHA from the Centro Nacional de Aceleradores of the University of Seville will be presented. The development of this equipment is intended to the study in situ of paintings in order to obtain depth profiles of pictorial layers by a no-destructive way. This investigation consists in studying the viability of this device for the study of pictorial layers of old paintings. The challenge consists in determining if the results obtained allow distinguishing the sequence of the paint layer and their composition. Several experimental paint multilayers have been analyzed to evaluate this setup. This paper shows that μXRF-CONCHA will be able to provide important information in order to understand and interpret the choice, palette, and technique of painters from the past.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015
ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either inte... more ABSTRACT Archeological silver–copper pieces often show surface enrichments in silver, either intentional or fortuitous. When this happens, non-destructive techniques like PIXE (Proton Induced X-ray Emission) and XRF (X-Ray Fluorescence) are not sufficient to access the whole bulk pieces because their penetration depths are typically of a few tens microns. If the archeological pieces cannot be cut or polished, it is necessary to apply other non-destructive techniques to access the bulk pieces. That way, archeological bronze pieces have been successfully studied combining XRF (or PIXE) with GRT (Gamma-Ray Transmission).
6H-SiC single crystalline substrates were implanted at room temperature with 2 MeV Al2+ ions to f... more 6H-SiC single crystalline substrates were implanted at room temperature with 2 MeV Al2+ ions to fluences from 2×1014 Al2+ cm-2 to 7×1014 Al2+ cm-2 and with different current densities (from 6.6 to 33×1010 Al2+ cm-2 s-1). The depth profile of the damage induced by the Al2+ ions was determined by Backscattering Spectrometry in channeling geometry (BS/C) with a 3.5 MeV He2+ beam. The BS/C spectra were evaluated using the RBX code. The samples were subsequently annealed at 1100°C in N2 for one hour, in order to analyze their structural recovery by BS/C and the amount of the remaining defects by means of Electron Paramagnetic Resonance (EPR). The results from the BS/C spectra corresponding to the as-implanted samples indicate that the damage depends strongly on the total fluence but also, although to a lesser extent, on the beam current density. The BS/C measurements reveal that all the samples, except the one implanted with the highest fluence, recover completely their original crystall...
Improûement of the high temperature oxidation behaûior of conûentional EN-1.4301 (AISI type 304) ... more Improûement of the high temperature oxidation behaûior of conûentional EN-1.4301 (AISI type 304) stainless steel was achieûed by implanting cerium ions. Implantation was performed in samples with two different surface treatments: commercial 2B mill finishing and preoxidation in synthetic air. One set of samples was annealed after implantation in order to recoûer the damage induced in the crystalline structure. Results show that the implantation of Ce greatly improûes the oxidation resistance at 1173 K of the EN-1.4301 grade stainless steels and that the annealing treatment after the implantation is beneficial during the subsequent oxidation. Experiments confirm the presence of spinel-type compounds and Cr 2 O 3 and Fe-Cr mixed oxides with high Cr content in the scale, and martensite being the dominating metallic phase. Chromium depletion in the near-surface layers is also described. Results are compared to preûiously published data on surface modification using La and Ce by pyrolysis of aerosols.
Improvement of the high temperature oxidation behavior of conventional EN-1.4301 (AISI type 304) ... more Improvement of the high temperature oxidation behavior of conventional EN-1.4301 (AISI type 304) stainless steel was achieved by implanting cerium ions. Implantation was performed in samples with two different surface treatments: commercial 2B mill finishing and preoxidation in synthetic air. One set of samples was annealed after implantation in order to recover the damage induced in the crystalline structure. Results
Bioactive glasses of different composition were ablated in vacuum with an ArF laser to investigat... more Bioactive glasses of different composition were ablated in vacuum with an ArF laser to investigate the transfer of the multi-component system to titanium substrates. Both the bioactive coatings and the bulk glasses were analysed by Rutherford backscattering spectrometry (RBS), particle induced X-ray emission (PIXE), nuclear reaction analysis (NRA), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopies (XPS). The composition analyses
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2008
In February 1998, almost 10 years ago, the setup of the first IBA (ion beam analysis) facility in... more In February 1998, almost 10 years ago, the setup of the first IBA (ion beam analysis) facility in Spain took place with the arrival of a 3 MV tandem accelerator [
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2011
... Red layered medieval stained glass window characterization by means of micro-PIXE technique. ... more ... Red layered medieval stained glass window characterization by means of micro-PIXE technique. ... of the hot fluid glass mixture could have been separated during the manufacturing process in order to produce a red glass mixture by adding a specific raw material that provided ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1995
... collected were bombarded with 2.5 MeV protons from the 3 MV Van de Graaff accelerator in the ... more ... collected were bombarded with 2.5 MeV protons from the 3 MV Van de Graaff accelerator in the ITN at Sacavèm (Portugal), and 20 ... 477-481 Beam Interactions with Materials & Atoms Environmental impact of fertilizer industries evaluated by PIXE JE Martin a, JP Bolivar b, MA ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997
Lanthanum ions of 100 keV have been implanted in AISI304 specimens at different doses. The erosio... more Lanthanum ions of 100 keV have been implanted in AISI304 specimens at different doses. The erosion or sputtering of the surface atoms, either from the steel matrix or already implanted, during the implantation process imposes a limitation on the maximum implantable dose. Hoping to increase this dose, we deposited thin layers of aluminium and alumina (Al,Os) on top of steel samples of similar composition and sputtering behaviour (AISI302). as the sputtering effect is much weaker on such species and this layer could also prevent the steel atoms from being removed from the surface. The experimental determination of the sputtering coefficients, total or partial, and its comparison with theoretical values, when possible, is another aim of this work.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1998
The evidence of the modi®cation of the surface structure of the AISI-304 stainless steel during t... more The evidence of the modi®cation of the surface structure of the AISI-304 stainless steel during the implantation of lanthanum makes the analysis of the sputtered elements very interesting. Those sputtered elements are deposited on a carbon sheet placed in front of the steel being implanted, and studied by means of RBS and PIXE, together with the implanted specimens. Besides, the protective eect of the implanted ions during the high temperature oxidation is also studied by those techniques together with XRD and thermogravimetric methods. Ó 1998 Elsevier Science B.V.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The recently created Centro Nacional de Aceleradores (National Center for Accelerators, CNA) in S... more The recently created Centro Nacional de Aceleradores (National Center for Accelerators, CNA) in Seville emerges as the ®rst ion beam analysis facility in Spain. The laboratory is based on a 3 MV tandem accelerator model 9SDH-2 of NEC and it is primarily focused on material research and modi®cation by means of IBA techniques: PIXE, RBS, NRA, PIGME and ERDA. The ions are delivered by two ion sources: Alphatross radio-frequency source and SNICS-II sputtering source. The ion beam handling system includes equipment for beam focusing, steering and diagnosis, a 90°a nalyzing magnet and a seven-port switcher magnet. A system based on magnetic steerers has been installed for highprecision beam energy scanning. In this paper the main elements of the laboratory will be described, focusing on the electronic equipment, detectors and the four beamlines planned for the moment: channeling line, microbeam line, multipurpose vacuum chamber and external microbeam. Moreover, the characteristics of the system as observed until now by means of performance tests, beam energy spread measurements and energy calibration experiments will be summarized.
La ciencia y el arte VI. Ciencias experimentales y conservación del patrimonio, 2017
The study of ancient metal artefacts includes nowadays the non-destructive analysis by means of c... more The study of ancient metal artefacts includes nowadays the non-destructive analysis by means of chemical-physical methods developed in the past decades. One of the most important parameters to be known from a sample is its chemical composition, as this information significantly contributes to the determination of several assumptions and to the response of many questions arisen from the study of a valuable heritage object. X-ray fluorescence is a well-known technique very much employed for the elemental analysis of ancient metal artefacts and the new implementation of a microfocused X-ray beam described in this text increases its applicability for the study of manufacture and decorative ancient techniques. This surface analytical method is complemented with the Gamma Ray Transmission technique, which has been employed in the bulk composition estimation of silver-copper coins and other copper based alloy samples. We also describe a portable confocal microfluorescence system developed by our Group to obtain non-destructive depth profiles.
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Papers by M. Respaldiza