Papers by Maria E. Reinoso
This work shows some advances in the study of rock art in Lago Traful area applying archaeometric... more This work shows some advances in the study of rock art in Lago Traful area applying archaeometric techniques. Physicochemical studies such as X-ray diffraction and Raman microspectroscopy, together with elementary analysis, were used to identify chromophores in mineral clasts recovered in archeological excavation and in superficial survey collections near the sites as well as on shelter art paintings. On the other hand, geographic information techniques were applied to design models about the circulation and exchange of information at the regional level. Iron based minerals were identified on green, red and yellow colored samples; calcined bones and calcite were found on white ones.Se presentan los avances en el estudio del arte rupestre en un sector ubicado al norte del Lago Traful, a partir de la aplicación de diferentes técnicas arqueométricas. Se utilizaron análisis físico químicos: difracción de rayos X y microespectroscopia Raman, complementados con análisis elementales para d...
Characterization of Natural Pigments from the Archaeological Context of Traful Lake (Neuquén, Argentina)
Latin American Antiquity, 2019
In this paper we discuss the use of mineral pigments recovered in stratigraphic position from thr... more In this paper we discuss the use of mineral pigments recovered in stratigraphic position from three excavated archaeological sites (Traful Lake area, Argentina) with the aim of providing information on selection and frequency of use of these raw materials. In this region, human occupation has been recorded since 4000 BP. In order to identify the chromophoric minerals, we applied wavelength dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and X-ray diffraction techniques. Green, red, yellow ochre, and white pigments dated between 3490 and 590 BP were analyzed. The results show that different analytical techniques provide complementary information in order to identify the pigments. Green, red, and yellow samples are related to iron-based compounds. The green pigments can be associated with celadonite and the others with hematite. White samples revealed the presence of hydroxyapatite. Black dots, identified as carbon, were observed in several samples. Red pigments are al...
Chungará (Arica), 2015
En este trabajo se presentan los resultados del análisis llevado a cabo sobre pigmentos de color ... more En este trabajo se presentan los resultados del análisis llevado a cabo sobre pigmentos de color negro pertenecientes a fragmentos cerámicos del estilo "negro sobre rojo", "negro y blanco sobre rojo" e "interior negro pulido"
Heritage Science, 2015
Introduction: Carbon-based pigments are a group of dark-colored materials, which are classified a... more Introduction: Carbon-based pigments are a group of dark-colored materials, which are classified according to the starting material used and their manufacturing process. Raman spectroscopy is an ideal technique for the identification of carbonaceous matter. Carbon-based pigments show broad bands between 1,300 and 1,600 cm −1 but they differ in position, width and relative intensity, allowing discrimination between them. The aim of the present study was the identification of carbon-based pigments in four polychrome wooden sculptures from the Jesuit Mission La Trinidad in Paraguay. Results: Analysis of the Raman spectral parameters of the polychrome samples and comparison with those of carbon-based pigment references allowed the identification of wood charcoal, lampblack, bistre and a black earth pigment. Complementary analysis by infrared spectroscopy and elemental analysis supported the assignments. Conclusions: In this study we have provided new evidence that Raman microscopy is a powerful technique for the discrimination of carbon-based pigments in works of art. This is the first time that bistre, lampblack and a black earth pigment are identified in colonial art. The chemical information obtained on the black pigments contributed to increase our knowledge on available resources and technology used in the manufacture of the polychrome sculptures at the Jesuit Mission. This information is relevant for our studies on Colonial art.
Boletín del Museo Chileno de Arte Precolombino, 2012
En las piezas cerámicas Negro sobre Rojo de la Quebrada de Humahuaca pueden observarse atributos ... more En las piezas cerámicas Negro sobre Rojo de la Quebrada de Humahuaca pueden observarse atributos tecnológicos que aportan información sobre su variabilidad local y cronológica. En este trabajo se realiza el análisis de pigmentos sobre muestras cerámicas procedentes de dicha región, mediante diversas técnicas arqueométricas. Algunas de uso ya común, como la microscopia óptica y la difracción de rayos X, y otras de más reciente aplicación, como la espectroscopia Raman y la microscopia electrónica de barrido con espectroscopia de energía dispersiva. La aplicación combinada de diversas técnicas y la discusión del caso con los distintos especialistas permitió establecer interpretaciones significativas a partir de los resultados obtenidos. Palabras clave: cerámica Estilo Negro sobre Rojo, Quebrada de Humahuaca, DRX, espectroscopia Raman, SEM-EDS Technological attributes that provide information about local and chronological variability can be observed in ceramic pieces Black-on-Red style from the Quebrada de Humahuaca. In this paper we offer an analysis of pigments from ceramic samples from that region that was carried out using a variety of arquaeometric techniques, including traditional ones such as optical microscopy and X-ray diffraction, as well as more recently developed ones such as Raman spectroscopy and SEM-EDS. The combined application of several archaeometric techniques and the case discussion with several experts yielded significant interpretations of the results obtained.
Boletín del Museo Chileno de Arte Precolombino, 2012
Se presentan resultados del estudio arqueométrico de pigmentos rojos y negros provenientes de dis... more Se presentan resultados del estudio arqueométrico de pigmentos rojos y negros provenientes de diseños pintados en cerámicas Vaquerías, estilo polícromo del Período Formativo del Noroeste Argentino. Se combinan las técnicas de espectroscopia Raman, difracción de rayos X (DRX) y microscopia electrónica de barrido con espectroscopia de energía dispersiva (SEM-EDS) para analizar la composición de los pigmentos en fragmentos de piezas cerámicas de los sitios Cardonal y Bordo Marcial (Catamarca, Argentina). Los pigmentos rojos están compuestos esencialmente de hematita; en los pigmentos negros se determinó alto contenido de manganeso y se confirmó la presencia de jacobsita y bixbyita. Palabras clave: Vaquerías, Noroeste Argentino, DRX, Raman, SEM-EDS, manganeso This paper presents the results of using archaeometric techniques to analyze red and black pigments from designs painted onto Vaquerías ceramics (a polychrome style of the Argentine Northwest Formative period). Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) were all employed in the compositional analysis of pigments on ceramic pieces from Cardonal and Bordo Marcial (Catamarca, Argentina) that were inhabited during the first two centuries of the Christian era. The red pigments have proven to be primarily hematite, while black pigments showed high contents of manganese and the presence of jacobsite and bixbyite.
International Journal of Pharmaceutics, 2007
This article was originally published in a journal published by Elsevier, and the attached copy i... more This article was originally published in a journal published by Elsevier, and the attached copy is provided by Elsevier for the author's benefit and for the benefit of the author's institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues that you know, and providing a copy to your institution's administrator.
Surface and Coatings Technology, 1999
Amorphous Si x C 1−x films, with x ranging from 0.30 to 0.70, were grown by high-energy ion beam ... more Amorphous Si x C 1−x films, with x ranging from 0.30 to 0.70, were grown by high-energy ion beam deposition starting from a methane-silane gas mixture. XPS analysis of the samples shows that it is possible to incorporate silicon to the amorphous carbon matrix giving an Si/C ratio depending on the methane-silane gas mixture. Raman spectra of the thermally annealed films indicate that the silicon incorporation in a-C films increases their thermal stability. There is no evidence of a complete graphitization up to 900°C, while in a-C samples graphitization occurs at about 500°C. This result shows that thermal stability is a function of the film composition.
Molecular dynamics simulation of the growth of thin films by deposition of carbon atoms and C60 molecules on diamond and silicon substrates
Physical Review B, 2005
The impact of C atoms and C60 molecules with ideal diamond and silicon (100) substrates and the s... more The impact of C atoms and C60 molecules with ideal diamond and silicon (100) substrates and the subsequent growth of carbon films have been investigated by molecular dynamics simulations. The interatomic many-body potential proposed by Tersoff has been used. The structural and vibrational properties of the as-grown and annealed films are studied as a function of the deposition energy (in the range 1-150eV for C atoms and 1-1000eV for C60 molecules) and are compared with experimental results. Analysis of films grown from C60 molecules reveals a behavior with deposition energy similar to that experimentally observed. For low deposition energies (below 100eV ) fullerene cages preserve their identity, constructing low-density structures with large intermolecular holes and practically no interface with the substrate. For higher deposition energies the molecules are broken into pieces, giving as a result high-density amorphous carbon films. Although the penetration depth of molecular fragments into the substrate increases with deposition energy, the resulting interface is considerably thinner than in the case of using individual atoms as projectiles. This is in agreement with experimental evidence of a poor adherence of films obtained by accelerating C60+ ions on silicon substrates.
Physical Review B, 2008
Amorphous carbon multilayered films have been studied by molecular dynamic simulations. Samples w... more Amorphous carbon multilayered films have been studied by molecular dynamic simulations. Samples were grown on diamond and silicon substrates, alternating deposition energies of 1 and 40 eV; atomic interactions were described by the semiemperical Tersoff potential. Structural analysis of the obtained films shows that the film density and sp 3 / sp 2 ratio oscillate with deposition energy. The alternation of layers with different local atomic stresses is also observed. High density sp 3-rich profiles and compressive stress are associated with high deposition energy regions, whereas low density sp 3 poor profiles and tensile stress are associated with low deposition energy ones. The grown films are thermally stable in the bulk under simulated annealing at 2500 K; appreciable changes, similar to those observed in monolayer films, occur mainly on the last superficial layer.
Carbon films obtained from fullerenes deposited on germanium: Experimental and simulated results
Physical Review B, 2006
In this work, carbon thin films have been experimentally produced by accelerating C60 ions on ger... more In this work, carbon thin films have been experimentally produced by accelerating C60 ions on germanium substrates at different deposition energies (from 50- 1000eV ). Adherence and chemical composition have been studied in order to characterize the obtained material. On the other hand, molecular dynamics simulations have been used to investigate the microscopic processes of the growth of carbon thin
Magnetism and electrode dependant resistive switching in Ca-doped ceramic bismuth ferrite
Materials Science and Engineering: B, 2012
ABSTRACT Here we report on the preparation and structural, magnetic and electrical characterizati... more ABSTRACT Here we report on the preparation and structural, magnetic and electrical characterization of BiFeO3 and Bi0.9Ca0.1FeO3 ceramic multiferroic samples. We suggest that Ca-doping creates oxygen vacancies and destabilizes the BiFeO3 spiral magnetic structure. We also study resistive switching effects in Bi0.9Ca0.1FeO3 with metallic electrodes, finding that the appearance of the effect is dependant on the fabrication procedure of the metallic electrode. On the basis of these observations, we critically revise some assumptions in currently available models of resistive switching of complex oxides.
Raman mapping analysis of pigments from Proas Iluminadas by Quinquela Martín
Journal of Cultural Heritage, 2012
ABSTRACT The painting Proas Iluminadas (Illuminated Bows) by Benito Quinquela Martín is studied b... more ABSTRACT The painting Proas Iluminadas (Illuminated Bows) by Benito Quinquela Martín is studied by Raman spectroscopy in order to analyse the technique and the pigments employed by the artist: ultramarine blue, carbon black, cadmium-sulphure based compounds for the hue of yellow, orange and red; also zinc white, barium yellow, massicot yellow and viridian were observed. The importance of using different excitation laser lines in the analysis of mixtures of pigments is highlighted. The Raman mapping analysis of cross section samples shows the way the artist composed the ground layer: a lead white stratum over a calcite one. It also allows distinguishing between a mixture of components and strata superposition, both presenting the same appearance under an optical microscope. This paper provides information about the materials and techniques used in a period of Argentine art not studied before from this point of view.
Diamond and Related Materials, 2001
Amorphous Si C films, with x ranging from 0 to 0.4, were grown by high-energy ion beam deposition... more Amorphous Si C films, with x ranging from 0 to 0.4, were grown by high-energy ion beam deposition. The mechanical x 1yx properties of these materials have been studied: indentation hardness, elastic modulus, wear resistance and scratch damage. It has been shown that the wear resistance and indentation behavior could not necessarily be correlated. Although these films do not show as high a hardness as other amorphous carbon films, their excellent wear resistance and thermal stability, as well as their very good adherence, make them suitable as protective coatings.
Carbon films obtained from a C60 fullerene ion beam
Diamond and Related Materials, 2002
Carbon films have been produced by accelerating C60+ ions on silicon substrates with energies bet... more Carbon films have been produced by accelerating C60+ ions on silicon substrates with energies between 100 and 800 eV. The resulting films have been characterized by Raman spectroscopy and electrical resistivity measurements. Different deposition regimes have been distinguished depending on the energy of the incident fullerenes. At low energies intermolecular covalent bonds begin to insinuate, while at higher energies there
Cement and Concrete Research, 2012
Several experimental techniques were used to characterise steel rebars embedded in concrete for 7... more Several experimental techniques were used to characterise steel rebars embedded in concrete for 70 years and exposed to mountain weather conditions in a sulphur-containing environment. The research has the objective of understanding the stages of rusting of steel in concrete in a non-conventional environment. Such understanding would provide information concerning the nature of the corrosion products formed on the steel rebars in order to make accurate predictions by means of analytical models.
Applied Surface Science, 2003
Carbon films have been produced by accelerating C 60 þ ions on silicon substrates with energies b... more Carbon films have been produced by accelerating C 60 þ ions on silicon substrates with energies between 100 and 800 eV. Furthermore some samples have been vacuum-annealed at 600 8C. The samples have been characterized by Raman and positron annihilation spectroscopies (RS-PAS). The measurements for the as-deposited material show that there is a coexistence of polymerized fullerenes and amorphous-carbon islands and that the structure depends on the energy of the incident ions. At low energies, fullerenes are deposited preserving the molecular identity and some intermolecular covalent bonds begin to insinuate; at higher energies, the amount of these covalent bonds increases and the amorphous islands predominate. After the annealing process, the amorphous phase organizes in graphitic clusters and the unbroken C 60 cages are transformed back to pristine and slightly polymerized C 60 .
Applied Surface Science, 2007
We report results of steel substrates coated with hard amorphous carbon and with diamond films. I... more We report results of steel substrates coated with hard amorphous carbon and with diamond films. In order to enhance the adherence to the substrate, steel substrates were pretreated by means of a silicon ion beam. Raman spectroscopy was used to analyze the structure of silicon interface while the elastic recoil detection analysis method was applied to determine their composition and thickness. The a-C adherence to the substrate and hardness were also tested. The diamond films were observed by SEM.
Applied Surface Science, 2006
Raman spectra, atomic force microscope (AFM) images, hardness (H) and Young's modulus (E) measure... more Raman spectra, atomic force microscope (AFM) images, hardness (H) and Young's modulus (E) measurements were carried out in order to characterize carbon thin films obtained from a C 60 ion beam on silicon substrates at different deposition energies (from 100 up to 500 eV). The mechanical properties were studied via the nanoindentation technique. It has been observed by Raman spectroscopy and AFM that the microstructure presents significant changes for films deposited at energies close to 300 eV. However, these remarkable changes have not been noticeable on the mechanical properties: apparently H and E increase with higher deposition energy up to $11 and $116 GPa, respectively. These values are underestimated if the influence of the film roughness is not taken into account.
Positron study of defects in a-SixC1−xfilms produced by ion beam deposition method
Applied Surface Science, 2001
Amorphous SixC1−x (a-SixC1−x) films with x ranging from 0 to 0.4 have been produced using a high ... more Amorphous SixC1−x (a-SixC1−x) films with x ranging from 0 to 0.4 have been produced using a high energy ion beam deposition method. The resulting films have been characterized by Raman annihilation spectroscopy and positron annihilation spectroscopy (PAS). Hardness and wear resistance have also been measured. It has been shown that the open volume defects and their distribution through the films
Uploads
Papers by Maria E. Reinoso