This page has only limited features, please log in for full access.

Prof. Carlo Meneghini
University Roma Tre, Science Department

Basic Info


Research Keywords & Expertise

0 Synchrotron powder diffraction
0 X-ray absorption spectroscopy (XAS)
0 Data analysis and statistics
0 Correlated and disordered many-body systems
0 material science & nanotechnology

Fingerprints

X-ray absorption spectroscopy (XAS)
Data analysis and statistics
Synchrotron powder diffraction

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
Profile ImageSimone Anzellini Diamond Light Source Ltd.
Profile ImageBarbara Capone Science Department, Universi...
Profile ImageGiuseppe Cruciani Department of Physics and Ea...
Profile ImageV. Raghavendra Reddy UGC-DAE Consortium for Scien...
Profile ImageSilvia Morante INFN, Sezione di Roma Tor Ve...
Profile ImageGiovanna Iucci University Roma tre, Dept. ...
Profile ImageS.D. Kaushik UGC-DAE Consortium for Scien...
Profile ImageFabiola Liscio Consiglio Nazionale delle Ri...
Following: 28 users
View all

Feed

Article
Published: 29 July 2021 in Physical Review B
Reads 0
Downloads 0

Colossal electroresistance (CER) in manganites, i.e., a large change in electrical resistance as a function of varying applied electric field or applied electric current, has often been described as complimentary to the colossal magnetoresistance (CMR) effect. Mixed valence vanadates with active t2g and empty eg orbitals, unlike manganites, have not naturally been discussed in this context, as double exchange based CMR is not realizable in them. However, presence of coupled spin and orbital degrees of freedom, metal-insulator transition (MIT) accompanied by orbital order-disorder transition, still make the vanadates important. Here we probe a Fe-doped hollandite lead vanadate PbFe1.75V4.25O11 (PFVO), which exhibits a clear MIT as a function of temperature. Most importantly, a giant fall in the resistivity, indicative of a CER, as well as a systematic shift in the MIT towards higher temperatures are observed with increasing applied current. Detailed structural, magnetic, thermodynamic, and transport studies point towards a complex interplay between the structural distortion, orbital order/disorder effect, and the resultant MIT and magnetic ordering in this system.

ACS Style

Rafikul Ali Saha; Abhisek Bandyopadhyay; Irene Schiesaro; Arnab Bera; Mintu Mondal; Carlo Meneghini; Sugata Ray. Colossal electroresistance response accompanied by metal-insulator transition in a mixed-valent vanadate. Physical Review B 2021, 104, 045149 .

AMA Style

Rafikul Ali Saha, Abhisek Bandyopadhyay, Irene Schiesaro, Arnab Bera, Mintu Mondal, Carlo Meneghini, Sugata Ray. Colossal electroresistance response accompanied by metal-insulator transition in a mixed-valent vanadate. Physical Review B. 2021; 104 (4):045149.

Chicago/Turabian Style

Rafikul Ali Saha; Abhisek Bandyopadhyay; Irene Schiesaro; Arnab Bera; Mintu Mondal; Carlo Meneghini; Sugata Ray. 2021. "Colossal electroresistance response accompanied by metal-insulator transition in a mixed-valent vanadate." Physical Review B 104, no. 4: 045149.

Review
Published: 09 July 2021 in Nanomaterials
Reads 0
Downloads 0

The design of novel multifunctional materials based on nanoparticles requires tuning of their magnetic properties, which are strongly dependent on the surface structure. The organic coating represents a unique tool to significantly modify the surface structure trough the bonds between the ligands of the organic molecule and the surface metal atoms. This work presents a critical overview of the effects of the organic coating on the magnetic properties of nanoparticles trough a selection of papers focused on different approaches to control the surface structure and the morphology of nanoparticles’ assemblies.

ACS Style

Maryam Abdolrahimi; Marianna Vasilakaki; Sawssen Slimani; Nikolaos Ntallis; Gaspare Varvaro; Sara Laureti; Carlo Meneghini; Kalliopi Trohidou; Dino Fiorani; Davide Peddis. Magnetism of Nanoparticles: Effect of the Organic Coating. Nanomaterials 2021, 11, 1787 .

AMA Style

Maryam Abdolrahimi, Marianna Vasilakaki, Sawssen Slimani, Nikolaos Ntallis, Gaspare Varvaro, Sara Laureti, Carlo Meneghini, Kalliopi Trohidou, Dino Fiorani, Davide Peddis. Magnetism of Nanoparticles: Effect of the Organic Coating. Nanomaterials. 2021; 11 (7):1787.

Chicago/Turabian Style

Maryam Abdolrahimi; Marianna Vasilakaki; Sawssen Slimani; Nikolaos Ntallis; Gaspare Varvaro; Sara Laureti; Carlo Meneghini; Kalliopi Trohidou; Dino Fiorani; Davide Peddis. 2021. "Magnetism of Nanoparticles: Effect of the Organic Coating." Nanomaterials 11, no. 7: 1787.

Journal article
Published: 17 June 2021 in Journal of Physics: Condensed Matter
Reads 0
Downloads 0

We have investigated magnetic, structural and dielectric properties of Bi\textsubscript{5}FeTi\textsubscript{3}O\textsubscript{15} (BFTO) in the temperature range 5K-300K. Using diffraction, Raman spectroscopy and x-ray absorption fine structure measurements, iso-structural modifications are observed at low temperatures ($\approx$ 100 K). The analysis of dielectric constant data revealed signatures of dielectric relaxation concomitant with these structural modifications in BFTO at the same temperatures. Further, employing complementary experimental methods, it is shown that the distribution of Fe/Ti ions in BFTO is random. With the help of techniques that probe magnetism at various length and time scales, it is shown that the phase-pure BFTO is non-magnetic down to the lowest temperatures.

ACS Style

Deepak Prajapat; Akash Surampalli; Irene Schiesaro; Som Datta Kaushik; Carlo Meneghini; Archna Sagdeo; Vasant G Sathe; V Siruguri; Edmund Welter; V Raghavendra Reddy. Lattice assisted dielectric relaxation in four-layer Aurivillius Bi5FeTi3O15 ceramic at low temperatures. Journal of Physics: Condensed Matter 2021, 1 .

AMA Style

Deepak Prajapat, Akash Surampalli, Irene Schiesaro, Som Datta Kaushik, Carlo Meneghini, Archna Sagdeo, Vasant G Sathe, V Siruguri, Edmund Welter, V Raghavendra Reddy. Lattice assisted dielectric relaxation in four-layer Aurivillius Bi5FeTi3O15 ceramic at low temperatures. Journal of Physics: Condensed Matter. 2021; ():1.

Chicago/Turabian Style

Deepak Prajapat; Akash Surampalli; Irene Schiesaro; Som Datta Kaushik; Carlo Meneghini; Archna Sagdeo; Vasant G Sathe; V Siruguri; Edmund Welter; V Raghavendra Reddy. 2021. "Lattice assisted dielectric relaxation in four-layer Aurivillius Bi5FeTi3O15 ceramic at low temperatures." Journal of Physics: Condensed Matter , no. : 1.

Journal article
Published: 11 June 2021 in Applied Sciences
Reads 0
Downloads 0

Synthesis atmosphere (i.e., air and nitrogen) effects on the physical properties and formation mechanism of spinel iron oxide nanoparticles prepared via the co-precipitation method have been investigated using a multi-technique approach. The obtained magnetic nanoparticles (MNPs) were characterized using the X-ray diffraction, transmission electron microscopy (TEM), SQUID magnetometry, Mössbauer spectroscopy and X-ray absorption near-edge Structure spectroscopy techniques. The synthesis procedure leads to the formation of a spinel structure with an average crystallite size of 9.0(9) nm. The morphology of the particles synthetized under an inert atmosphere was quasi-spherical, while the nanoparticles prepared in air present a faceted shape. The small differences observed in morphological properties are explained by the influence of the reaction atmosphere on the formation mechanism of the MNPs. The magnetic characterization indicates that both samples exhibit superparamagnetic behavior at 300 K. The investigation by means of the Langevin approach at 300 K also leads to equal values for the mean size of the magnetic cores (Dm). Additionally, the analysis of the Mössbauer spectra revealed the lack of spin disorder for both samples, resulting in a high saturation magnetization. The fit of XANES spectrum suggests that about 2/3 of the iron ions reside in a local environment close to that of γ-Fe2O3 and about 1/3 close to that of Fe3O4 for the sample synthetized in inert atmosphere.

ACS Style

Sawssen Slimani; Carlo Meneghini; Maryam Abdolrahimi; Alessandro Talone; Jean Murillo; Gianni Barucca; Nader Yaacoub; Patrizia Imperatori; Erzsébet Illés; Mourad Smari; Essebti Dhahri; Davide Peddis. Spinel Iron Oxide by the Co-Precipitation Method: Effect of the Reaction Atmosphere. Applied Sciences 2021, 11, 5433 .

AMA Style

Sawssen Slimani, Carlo Meneghini, Maryam Abdolrahimi, Alessandro Talone, Jean Murillo, Gianni Barucca, Nader Yaacoub, Patrizia Imperatori, Erzsébet Illés, Mourad Smari, Essebti Dhahri, Davide Peddis. Spinel Iron Oxide by the Co-Precipitation Method: Effect of the Reaction Atmosphere. Applied Sciences. 2021; 11 (12):5433.

Chicago/Turabian Style

Sawssen Slimani; Carlo Meneghini; Maryam Abdolrahimi; Alessandro Talone; Jean Murillo; Gianni Barucca; Nader Yaacoub; Patrizia Imperatori; Erzsébet Illés; Mourad Smari; Essebti Dhahri; Davide Peddis. 2021. "Spinel Iron Oxide by the Co-Precipitation Method: Effect of the Reaction Atmosphere." Applied Sciences 11, no. 12: 5433.

Conference paper
Published: 23 May 2021 in Theoretical Frontiers in Black Holes and Cosmology
Reads 0
Downloads 0

In recent years the biomedical research has focused on new metal-based anticancer drugs. Among them Cu-based antitumor agents are arising some attention based on the observation that endogenous metals appear to be less toxic toward normal cells with respect to cancer ones. Conjugating the Cu(II) complexes with hydrophilic gold nanoparticles (Au-NPs) appears a promising way, suitable to improve the complexes solubility and stability in water and to raise their bioavailability. In this context, we investigated the valence state and coordination chemistry of Cu for a selection of Cu-complexes suitable for grafting on Au-NPs. The Cu K-edge XAFS data were analysed in the near edge (XANES) and extended (EXAFS) regions to obtain preliminary characterization aimed at understanding local coordination chemistry and electronic structure of Cu.

ACS Style

Irene Schiesaro; Iole Venditti; Maura Pellei; Carlo Santini; Luca Bagnarelli; Giovanna Iucci; Chiara Battocchio; Carlo Meneghini. Metal Coordination Core in Copper(II) Complexes Investigated by XAFS. Theoretical Frontiers in Black Holes and Cosmology 2021, 169 -179.

AMA Style

Irene Schiesaro, Iole Venditti, Maura Pellei, Carlo Santini, Luca Bagnarelli, Giovanna Iucci, Chiara Battocchio, Carlo Meneghini. Metal Coordination Core in Copper(II) Complexes Investigated by XAFS. Theoretical Frontiers in Black Holes and Cosmology. 2021; ():169-179.

Chicago/Turabian Style

Irene Schiesaro; Iole Venditti; Maura Pellei; Carlo Santini; Luca Bagnarelli; Giovanna Iucci; Chiara Battocchio; Carlo Meneghini. 2021. "Metal Coordination Core in Copper(II) Complexes Investigated by XAFS." Theoretical Frontiers in Black Holes and Cosmology , no. : 169-179.

Conference paper
Published: 23 May 2021 in Theoretical Frontiers in Black Holes and Cosmology
Reads 0
Downloads 0

The physical properties of nanostructured thin films and multilayers depend crucially on their interfaces. The precise knowledge of the interface morphology at the atomic scale is mandatory to reliably understand their macroscopic response. These details become even more critical when dealing with magnetic thin films as the finest structural and/or compositional local changes may affect the magnetic coupling and alter the macroscopic response. Soft X-ray Resonant Magnetic Reflectivity (SXRMR) is a suitable technique in this field, combining specific aspects of x-ray absorption and x-ray scattering processes to simultaneously obtain complementary structural and magnetic information on thin films and multilayers. Here, we present a case study on a MgO/Co/MgO trilayer in which the combined use of SXRMR, x-ray absorption spectroscopy and x-ray magnetic circular dichroism has allowed to reconstruct the elemental and magnetic depth profiles with sub-nanometric resolution and to distinguish fine compositional defects at the Co-on-MgO and MgO-on-Co interfaces.

ACS Style

Ilaria Carlomagno; Adriano Verna; Thomas Forrest; Carlo Meneghini. Structural Profile of a MgO/Co/MgO Trilayer Using Soft X-ray Resonant Magnetic Reflectivity. Theoretical Frontiers in Black Holes and Cosmology 2021, 155 -167.

AMA Style

Ilaria Carlomagno, Adriano Verna, Thomas Forrest, Carlo Meneghini. Structural Profile of a MgO/Co/MgO Trilayer Using Soft X-ray Resonant Magnetic Reflectivity. Theoretical Frontiers in Black Holes and Cosmology. 2021; ():155-167.

Chicago/Turabian Style

Ilaria Carlomagno; Adriano Verna; Thomas Forrest; Carlo Meneghini. 2021. "Structural Profile of a MgO/Co/MgO Trilayer Using Soft X-ray Resonant Magnetic Reflectivity." Theoretical Frontiers in Black Holes and Cosmology , no. : 155-167.

Journal article
Published: 25 March 2021 in Crystals
Reads 0
Downloads 0

In the present study, the local atomic structure of a Nb3Sn superconductor sample has been probed by X-ray absorption fine structure (XAFS) as a function of hydrostatic pressure (from ambient up to 26 GPa) using a diamond anvil cell set-up. The analysis of the Nb-K edge extended X-ray absorption fine structure (EXAFS) data was carried out combining standard multi shell structural refinement and reverse Monte Carlo method to provide detailed in situ characterization of the pressure-induced evolution of the Nb local structure in Nb3Sn. The results highlight a complex evolution of Nb chains at the local atomic scale, with a peculiar correlated displacement of Nb–Nb and Nb–Nb–Nb configurations. Such a local effect appears related to anomalies evidenced by X-ray diffraction in other superconductors belonging to the same A15 crystallographic structure.

ACS Style

Irene Schiesaro; Simone Anzellini; Rita Loria; Raffaella Torchio; Tiziana Spina; René Flükiger; Tetsuo Irifune; Enrico Silva; Carlo Meneghini. Anomalous Behavior in the Atomic Structure of Nb3Sn under High Pressure. Crystals 2021, 11, 331 .

AMA Style

Irene Schiesaro, Simone Anzellini, Rita Loria, Raffaella Torchio, Tiziana Spina, René Flükiger, Tetsuo Irifune, Enrico Silva, Carlo Meneghini. Anomalous Behavior in the Atomic Structure of Nb3Sn under High Pressure. Crystals. 2021; 11 (4):331.

Chicago/Turabian Style

Irene Schiesaro; Simone Anzellini; Rita Loria; Raffaella Torchio; Tiziana Spina; René Flükiger; Tetsuo Irifune; Enrico Silva; Carlo Meneghini. 2021. "Anomalous Behavior in the Atomic Structure of Nb3Sn under High Pressure." Crystals 11, no. 4: 331.

Journal article
Published: 19 March 2021 in Sustainability
Reads 0
Downloads 0

The conservation of underground tombs is affected by several physical-chemical and biological factors, which could be reduced by insulating systems able to maintain the microclimatic stability also decreasing the biodeterioration risk. In Mediterranean areas, wild ephemeral plants, which reduce their cover during the hot season, seem unsuitable for reducing summer overheating. In this study, we wish to assess the influence of vegetation cover and of overlaying soil, after the establishment of an evergreen turf of a cultivar of Cynodon dactylon, on two tombs in the Etruscan Necropolis of Monterozzi, covered by linear-shaped tumuli. Therefore, we evaluated for 10 months the thermo-hygrometric values of these tombs, together with two tombs as controls. We also evaluated the different tumuli’s morphologies and the related received solar radiation. Results confirmed that late summer and early autumn as critical microclimatic periods for the risk factors of hypogeal paintings when peaks of superficial temperature occur. A positive influence of vegetation cover on maintaining constant humidity and internal temperatures was detected, but the mounds orientation, as well as soil depth, seems to have a relevant role. Considering the naturalistic features of the area and the related cultural ecosystem services, a careful selection of wild plants is suggested.

ACS Style

Giulia Caneva; Simone Langone; Flavia Bartoli; Adele Cecchini; Carlo Meneghini. Vegetation Cover and Tumuli’s Shape as Affecting Factors of Microclimate and Biodeterioration Risk for the Conservation of Etruscan Tombs (Tarquinia, Italy). Sustainability 2021, 13, 3393 .

AMA Style

Giulia Caneva, Simone Langone, Flavia Bartoli, Adele Cecchini, Carlo Meneghini. Vegetation Cover and Tumuli’s Shape as Affecting Factors of Microclimate and Biodeterioration Risk for the Conservation of Etruscan Tombs (Tarquinia, Italy). Sustainability. 2021; 13 (6):3393.

Chicago/Turabian Style

Giulia Caneva; Simone Langone; Flavia Bartoli; Adele Cecchini; Carlo Meneghini. 2021. "Vegetation Cover and Tumuli’s Shape as Affecting Factors of Microclimate and Biodeterioration Risk for the Conservation of Etruscan Tombs (Tarquinia, Italy)." Sustainability 13, no. 6: 3393.

Journal article
Published: 10 March 2021 in Environmental Pollution
Reads 0
Downloads 0

To understand the fate of plastic in oceans and the interaction with marine organisms, we investigated the incorporation of (bio)polymers and microplastics in selected benthic foraminiferal species by applying FTIR (Fourier Transform Infrared) microscopy. This experimental methodology has been applied to cultured benthic foraminifera Rosalina globularis, and to in situ foraminifera collected in a plastic remain found buried into superficial sediment in the Mediterranean seafloor, Rosalina bradyi, Textularia bocki and Cibicidoides lobatulus. In vitro foraminifera were treated with bis-(2-ethylhexyl) phthalate (DEHP) molecule to explore its internalization in the cytoplasm. Benthic foraminifera are marine microbial eukaryotes, sediment-dwelling, commonly short-lived and with reproductive cycles which play a central role in global biogeochemical cycles of inorganic and organic compounds. Despite the recent advances and investigations into the occurrence, distribution, and abundance of plastics, including microplastics, in marine environments, there remain relevant knowledge gaps, particularly on their effects on the benthic protists. No study, to our knowledge, has documented the molecular scale effect of plastics on foraminifera. Our analyses revealed three possible ways through which plastic-related molecules and plastic debris can enter a biogeochemical cycle and may affect the ecosystems: 1) foraminifera in situ can grow on plastic remains, namely C. lobatulus, R. bradyi and T. bocki, showing signals of oxidative stress and protein aggregation in comparison with R. globularis cultured in negative control; 2) DEHP can be incorporated in the cytoplasm of calcareous foraminifera, as observed in R. globularis; 3) microplastic debris, identified as epoxy resin, can be found in the cytoplasm and the agglutinated shell of T. bocki. We hypothesize that plastic waste and their associated additives may produce modifications related to the biomineralization process in foraminifera. This effect would be added to those induced by ocean acidification with negative consequences on the foraminiferal biogenic carbon (C) storage capacity.

ACS Style

Giovanni Birarda; Carla Buosi; Francesca Caridi; Maria Antonietta Casu; Giovanni De Giudici; Letizia Di Bella; Daniela Medas; Carlo Meneghini; Martina Pierdomenico; Anna Sabbatini; Artur Surowka; Lisa Vaccari. Plastics, (bio)polymers and their apparent biogeochemical cycle: An infrared spectroscopy study on foraminifera. Environmental Pollution 2021, 279, 116912 .

AMA Style

Giovanni Birarda, Carla Buosi, Francesca Caridi, Maria Antonietta Casu, Giovanni De Giudici, Letizia Di Bella, Daniela Medas, Carlo Meneghini, Martina Pierdomenico, Anna Sabbatini, Artur Surowka, Lisa Vaccari. Plastics, (bio)polymers and their apparent biogeochemical cycle: An infrared spectroscopy study on foraminifera. Environmental Pollution. 2021; 279 ():116912.

Chicago/Turabian Style

Giovanni Birarda; Carla Buosi; Francesca Caridi; Maria Antonietta Casu; Giovanni De Giudici; Letizia Di Bella; Daniela Medas; Carlo Meneghini; Martina Pierdomenico; Anna Sabbatini; Artur Surowka; Lisa Vaccari. 2021. "Plastics, (bio)polymers and their apparent biogeochemical cycle: An infrared spectroscopy study on foraminifera." Environmental Pollution 279, no. : 116912.

Journal article
Published: 20 February 2021 in Journal of Cultural Heritage
Reads 0
Downloads 0

Artemidorus papyrus has been the subject of a longstanding dispute around its authenticity. The 2.5 m long document, presents a multiplicity of writings, on both sides. Some historians support the papyrus’ multiple life hypothesis (PMLH): the different writings appearing on the document, would correspond to three time periods (1st BC–1st AD) called the “three lives of the papyrus”. A possible way to assess whether the document has been written in different eras, is the analysis of the graphic materials employed; a heterogeneous formulation of the inks used throughout the papyrus as a whole, together with a local homogeneity in defined regions, would support PMLH. To unveil this paradigm, we performed an in-depth investigation of the inks on the papyrus, by collecting their Raman spectra on a statistical relevant number of samples belonging to the different regions of the document. We found a wide variety of carbon-based inks that appear to be randomly distributed on the entire surface. Different ordered, disordered, crystalline or amorphous structures might coexist in carbon-based materials, due to the different hybridisations of the carbon. All of the different structures appear as peaks, shoulders or sub peaks that are convoluted in the global spectrum, thus rendering the attribution of Raman peaks as an extremely complex task. In order to support and guide our analysis, we therefore implemented a Principal Component Analysis (PCA) aimed at performing a two-step comparison between the Artemidorus inks Raman spectra and an ample reference spectral library on carbon-based materials that we built specifically for this study. A first PCA screening was used to restrict the analysis for similarity between the experimental spectra and the library of standards to a subset of compounds. It was indeed possible to define a cluster in the Principal Component subspace that contained only a few standards and the whole set of Artemidorus spectra. It is interesting to notice that, among the possibilities in the reference library, our analysis also found two pigments manufactured with modern industrial methods: Carbon black (after 1870) and lampblack (after 1740, modified in 19th c.). A second PCA, performed on the subset of the standard spectra individuated, allowed to highlight the regions of the Raman spectra where the Artemidorus data depict significant differences with respect to their reference standards, thus allowing for a guided deconvolution of the Raman peaks. This study demonstrates that it is not possible to define neat regions on the papyrus that would be identifiable through the usage of different groups of inks, as the same subset of inks is distributed on all of the document. It is therefore impossible to recognise areas of the papyrus where the local usage of specific and region-dependent graphic materials would lead to chronologically distinguishable writings and drawings. This allows us to confute the “three lives hypothesis”.

ACS Style

Barbara Capone; Paola Biocca; Pietro Corsi; Carlo Meneghini; Marina Bicchieri. Does the Artemidorus papyrus have multiple lives? Seeking for the answer in the inks through a Raman and PCA analysis. Journal of Cultural Heritage 2021, 48, 1 -10.

AMA Style

Barbara Capone, Paola Biocca, Pietro Corsi, Carlo Meneghini, Marina Bicchieri. Does the Artemidorus papyrus have multiple lives? Seeking for the answer in the inks through a Raman and PCA analysis. Journal of Cultural Heritage. 2021; 48 ():1-10.

Chicago/Turabian Style

Barbara Capone; Paola Biocca; Pietro Corsi; Carlo Meneghini; Marina Bicchieri. 2021. "Does the Artemidorus papyrus have multiple lives? Seeking for the answer in the inks through a Raman and PCA analysis." Journal of Cultural Heritage 48, no. : 1-10.

Journal article
Published: 08 January 2021 in Journal of Physics: Condensed Matter
Reads 0
Downloads 0

This work reports about a novel approach for investigating surface processes during the early stages of galvanic corrosion of stainless steel in situ by employing ultra-thin films and synchrotron X-radiation. Characterized by X-ray techniques and voltammetry, such films, sputter deposited from austenitic steel, were found representing useful replicas of the target material. Typical for stainless steel, the surface consists of a passivation layer of Fe- and Cr-oxides, a couple of nm thick, that is depleted of Ni. Films of ≈ 4 nm thickness were studied in situ in an electrochemical cell under potential control (-0.6 to +0.8 V vs Ag/AgCl) during exposure to 0.1 M KCl. Material transport was recorded with better than 1/10 monolayer sensitivity by X-ray spectroscopy. Leaching of Fe was observed in the cathodic range and the therefor necessary reduction of Fe-oxide appears to be accelerated by atomic hydrogen. Except for minor leaching, reduction of Ni, while expected from Pourbaix diagram, was not observed until at ≈ +0.8 V Cr-oxide was removed from the film. After couple of minutes exposure at +0.8 V, the current in the electrochemical cell revealed a rapid pitting event that was simultaneously monitored by X-ray spectroscopy. Continuous loss of Cr and Ni was observed during the induction time leading to the pitting, suggesting a causal connection with the event. Finally, a spectroscopic image of a pit was recorded ex situ with 50 nm lateral and 1 nm depth resolution by soft X-ray scanning absorption microscopy at the Fe L2,3-edges by using a 80 nm film on a SiN membrane, which is further demonstrating the usefulness of thin films for corrosion studies.

ACS Style

Debi Garai; Vladyslav Solokha; Axel Wilson; Illaria Carlomagno; Ajay Gupta; Mukul Gupta; V Raghavendra Reddy; Carlo Meneghini; Francesco Carla; Christian Morawe; Jörg Zegenhagen. Studying the onset of galvanic steel corrosion in situ using thin films: film preparation, characterization and application to pitting. Journal of Physics: Condensed Matter 2021, 33, 125001 .

AMA Style

Debi Garai, Vladyslav Solokha, Axel Wilson, Illaria Carlomagno, Ajay Gupta, Mukul Gupta, V Raghavendra Reddy, Carlo Meneghini, Francesco Carla, Christian Morawe, Jörg Zegenhagen. Studying the onset of galvanic steel corrosion in situ using thin films: film preparation, characterization and application to pitting. Journal of Physics: Condensed Matter. 2021; 33 (12):125001.

Chicago/Turabian Style

Debi Garai; Vladyslav Solokha; Axel Wilson; Illaria Carlomagno; Ajay Gupta; Mukul Gupta; V Raghavendra Reddy; Carlo Meneghini; Francesco Carla; Christian Morawe; Jörg Zegenhagen. 2021. "Studying the onset of galvanic steel corrosion in situ using thin films: film preparation, characterization and application to pitting." Journal of Physics: Condensed Matter 33, no. 12: 125001.

Research article
Published: 15 November 2020 in The Journal of Physical Chemistry C
Reads 0
Downloads 0

In this work, the electronic and molecular structure, as well as the morphology, of innovative nanostructured materials whose optical properties respond to the presence of heavy metals in water samples was investigated. In particular, the here discussed silver nanoparticles (NPs) stabilized by a hydrophilic ligand (sodium 3-mercapto-1-propanesulfonate, 3MPS) are able to reveal the presence of mercury ions at ppm levels. The sensitivity of the proposed nanosensor to Hg(II) in 1–5 ppm range was ascertained by optical tests; then, the local chemistry and electronic structure of the nanostructured coordination compounds made of functionalized silver nanoparticles (NPs) and metal ions, and their correlation with the resulting nanoaggregates’ shape and morphology, were investigated by state-of-the-art synchrotron radiation (SR)-induced spectroscopies and transmission electron microscopy (TEM). In particular, SR-induced X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) measurements allowed us to gather complementary information about the silver–mercury interaction, which is only partially mediated by the negatively charged 3MPS ligand, different from what was observed for analogous nanosensors applied to other bivalent heavy metal ions, for example, Co(II) and Ni(II). TEM morphological analysis sheds light on the structure of the AgNP-3MPS/Hg aggregates, revealing the formation of Ag/Hg alloy nanoparticles.

ACS Style

Irene Schiesaro; Luca Burratti; Carlo Meneghini; Ilaria Fratoddi; Paolo Prosposito; Joohyun Lim; Christina Scheu; Iole Venditti; Giovanna Iucci; Chiara Battocchio. Hydrophilic Silver Nanoparticles for Hg(II) Detection in Water: Direct Evidence for Mercury–Silver Interaction. The Journal of Physical Chemistry C 2020, 124, 25975 -25983.

AMA Style

Irene Schiesaro, Luca Burratti, Carlo Meneghini, Ilaria Fratoddi, Paolo Prosposito, Joohyun Lim, Christina Scheu, Iole Venditti, Giovanna Iucci, Chiara Battocchio. Hydrophilic Silver Nanoparticles for Hg(II) Detection in Water: Direct Evidence for Mercury–Silver Interaction. The Journal of Physical Chemistry C. 2020; 124 (47):25975-25983.

Chicago/Turabian Style

Irene Schiesaro; Luca Burratti; Carlo Meneghini; Ilaria Fratoddi; Paolo Prosposito; Joohyun Lim; Christina Scheu; Iole Venditti; Giovanna Iucci; Chiara Battocchio. 2020. "Hydrophilic Silver Nanoparticles for Hg(II) Detection in Water: Direct Evidence for Mercury–Silver Interaction." The Journal of Physical Chemistry C 124, no. 47: 25975-25983.

Paper
Published: 05 October 2020 in Dalton Transactions
Reads 0
Downloads 0

New hexyl bis(pyrazol-1-yl)acetate copper(ii) complexes as efficient catalysts for allylic oxidation by the Kharasch–Sosnovsky reaction.

ACS Style

Serena Gabrielli; Maura Pellei; Iole Venditti; Ilaria Fratoddi; Chiara Battocchio; Giovanna Iucci; Irene Schiesaro; Carlo Meneghini; Alessandro Palmieri; Enrico Marcantoni; Luca Bagnarelli; Riccardo Vallesi; Carlo Santini. Development of new and efficient copper(ii) complexes of hexyl bis(pyrazolyl)acetate ligands as catalysts for allylic oxidation. Dalton Transactions 2020, 49, 15622 -15632.

AMA Style

Serena Gabrielli, Maura Pellei, Iole Venditti, Ilaria Fratoddi, Chiara Battocchio, Giovanna Iucci, Irene Schiesaro, Carlo Meneghini, Alessandro Palmieri, Enrico Marcantoni, Luca Bagnarelli, Riccardo Vallesi, Carlo Santini. Development of new and efficient copper(ii) complexes of hexyl bis(pyrazolyl)acetate ligands as catalysts for allylic oxidation. Dalton Transactions. 2020; 49 (44):15622-15632.

Chicago/Turabian Style

Serena Gabrielli; Maura Pellei; Iole Venditti; Ilaria Fratoddi; Chiara Battocchio; Giovanna Iucci; Irene Schiesaro; Carlo Meneghini; Alessandro Palmieri; Enrico Marcantoni; Luca Bagnarelli; Riccardo Vallesi; Carlo Santini. 2020. "Development of new and efficient copper(ii) complexes of hexyl bis(pyrazolyl)acetate ligands as catalysts for allylic oxidation." Dalton Transactions 49, no. 44: 15622-15632.

Research letter
Published: 14 July 2020 in Geophysical Research Letters
Reads 0
Downloads 0

Nickel is the second most abundant element in the Earth's core. However, the properties of Fe‐Ni alloys are still poorly constrained under planetary cores conditions, in particular concerning the effect of Ni on the melting curve of Fe. Here we show that Ni alloying up to 36 wt% does not affect the melting curve of Fe up to 100 GPa. However, Ni strongly modifies the hexagonal‐closed‐packed/face‐centered‐cubic (hcp/fcc) phase boundary, pushing the hcp/fcc/liquid triple point of Fe‐20wt%Ni to higher pressures and temperatures. Our results allow constraining the triple point for Fe‐10wt%Ni, a composition relevant for the Earth interior, and point out a decrease of the melting temperature at core‐mantle boundary by 400 K with respect to pure Fe. A lower amount of light elements than previously predicted is thus required to reduce the crystallization temperature of core materials below that of a peridotitic lower mantle, in better agreement with geochemical observations.

ACS Style

R. Torchio; S. Boccato; F. Miozzi; A. D. Rosa; N. Ishimatsu; I. Kantor; N. Sévelin‐Radiguet; R. Briggs; C. Meneghini; T. Irifune; G. Morard. Melting Curve and Phase Relations of Fe‐Ni Alloys: Implications for the Earth's Core Composition. Geophysical Research Letters 2020, 47, 1 .

AMA Style

R. Torchio, S. Boccato, F. Miozzi, A. D. Rosa, N. Ishimatsu, I. Kantor, N. Sévelin‐Radiguet, R. Briggs, C. Meneghini, T. Irifune, G. Morard. Melting Curve and Phase Relations of Fe‐Ni Alloys: Implications for the Earth's Core Composition. Geophysical Research Letters. 2020; 47 (14):1.

Chicago/Turabian Style

R. Torchio; S. Boccato; F. Miozzi; A. D. Rosa; N. Ishimatsu; I. Kantor; N. Sévelin‐Radiguet; R. Briggs; C. Meneghini; T. Irifune; G. Morard. 2020. "Melting Curve and Phase Relations of Fe‐Ni Alloys: Implications for the Earth's Core Composition." Geophysical Research Letters 47, no. 14: 1.

Journal article
Published: 12 March 2020 in Minerals
Reads 0
Downloads 0

Environmental contamination due to human activities is a worldwide problem that has led to the development of different remediation techniques, including biotechnological approaches such as phytoextraction and phytostabilization. These techniques take advantage of pioneer plants that naturally develop tolerance mechanisms to survive in extreme environments. A multi-technique and multi-disciplinary approach was applied for the investigation of Helichrysum microphyllum subsp. tyrrhenicum samples, bulk soil, and rhizospheres collected from a metal-extreme environment (Zn-Pb mine of Campo Pisano, SW Sardinia, Italy). Zinc, Pb, and Cd are the most abundant metals, with Zn attaining 3 w/w% in the rhizosphere solid materials, inducing oxidative stress in the roots as revealed by infrared microspectroscopy (IR). X-ray diffraction (XRD), scanning electron microscopy (SEM), and chemical analysis coupled with synchrotron radiation-based (SR) techniques demonstrate that quartz, dolomite, and weddellite biominerals precipitate in roots, stems, and leaves, likely as a response to environmental stress. In the rhizosphere, Zn chemical speciation is mainly related to the Zn ore minerals (smithsonite and hydrozincite) whereas, in plant tissues, Zn is primarily bound to organic compounds such as malate, cysteine, and histidine molecules that act as metal binders and, eventually, detoxification agents for the Zn excess. These findings suggest that H. microphyllum subsp. tyrrhenicum has developed its own adaptation strategy to survive in polluted substrates, making it a potential candidate for phytostabilization aimed at mitigating the dispersion of metals in the surrounding areas.

ACS Style

Maria Enrica Boi; Daniela Medas; Giuliana Aquilanti; Gianluigi Bacchetta; Giovanni Birarda; Giovanna Cappai; Ilaria Carlomagno; Maria Antonietta Casu; Alessandra Gianoncelli; Carlo Meneghini; Martina Piredda; Francesca Podda; Marco Porceddu; Valentina Rimondi; Lisa Vaccari; Giovanni De Giudici. Mineralogy and Zn Chemical Speciation in a Soil-Plant System from a Metal-Extreme Environment: A Study on Helichrysum microphyllum subsp. tyrrhenicum (Campo Pisano Mine, SW Sardinia, Italy). Minerals 2020, 10, 259 .

AMA Style

Maria Enrica Boi, Daniela Medas, Giuliana Aquilanti, Gianluigi Bacchetta, Giovanni Birarda, Giovanna Cappai, Ilaria Carlomagno, Maria Antonietta Casu, Alessandra Gianoncelli, Carlo Meneghini, Martina Piredda, Francesca Podda, Marco Porceddu, Valentina Rimondi, Lisa Vaccari, Giovanni De Giudici. Mineralogy and Zn Chemical Speciation in a Soil-Plant System from a Metal-Extreme Environment: A Study on Helichrysum microphyllum subsp. tyrrhenicum (Campo Pisano Mine, SW Sardinia, Italy). Minerals. 2020; 10 (3):259.

Chicago/Turabian Style

Maria Enrica Boi; Daniela Medas; Giuliana Aquilanti; Gianluigi Bacchetta; Giovanni Birarda; Giovanna Cappai; Ilaria Carlomagno; Maria Antonietta Casu; Alessandra Gianoncelli; Carlo Meneghini; Martina Piredda; Francesca Podda; Marco Porceddu; Valentina Rimondi; Lisa Vaccari; Giovanni De Giudici. 2020. "Mineralogy and Zn Chemical Speciation in a Soil-Plant System from a Metal-Extreme Environment: A Study on Helichrysum microphyllum subsp. tyrrhenicum (Campo Pisano Mine, SW Sardinia, Italy)." Minerals 10, no. 3: 259.

Journal article
Published: 01 November 2019 in Physica B: Condensed Matter
Reads 0
Downloads 0

Considering the proposed structural anomaly in the “topotactically” reduced compound CaMnO2, we investigated its local structure through extended x-ray absorption fine structure (EXAFS) spectroscopy. The in-depth analysis of the EXAFS results unraveled an unforeseen local chemical order of Mn and Ca, which helps to advance the previous understanding of average disordered scenario, obtained based on diffraction probes like x-ray and neutron. We established the microscopic origin of such locally ordered structure on the basis of Mn-O covalency through analysis of density functional theory calculations. Further, fluorination is attempted to explore the influence of modification of the anionic network and bond covalency. We found that the more ionic Mn-F bonds, compared to Mn-O bonds, drive a local phase separation between Mn-rich phase and Ca-rich phase.

ACS Style

Payel Aich; Shreya Das; Carlo Meneghini; Irene Schiesaro; Tanusri Saha-Dasgupta; Sugata Ray. Re-examining the nature of ordering in CaMnO2: The role of Mn-O covalency in the local structure. Physica B: Condensed Matter 2019, 581, 411837 .

AMA Style

Payel Aich, Shreya Das, Carlo Meneghini, Irene Schiesaro, Tanusri Saha-Dasgupta, Sugata Ray. Re-examining the nature of ordering in CaMnO2: The role of Mn-O covalency in the local structure. Physica B: Condensed Matter. 2019; 581 ():411837.

Chicago/Turabian Style

Payel Aich; Shreya Das; Carlo Meneghini; Irene Schiesaro; Tanusri Saha-Dasgupta; Sugata Ray. 2019. "Re-examining the nature of ordering in CaMnO2: The role of Mn-O covalency in the local structure." Physica B: Condensed Matter 581, no. : 411837.

Article
Published: 18 October 2019 in Physical Review B
Reads 0
Downloads 0

The structural and dielectric characterization of 30% Sn-doped BaTiO3 (BaSn0.3Ti0.7O3) as a function of temperature is carried out combining, complementary probes to reveal structural modifications associated to the relaxor behavior. Dielectric data confirms the existence of relaxor-type behavior in BaSn0.3Ti0.7O3. The local and average structural changes as a function of temperature have been investigated in the region of broad changes of dielectric response. Local probes, such as x-ray absorption fine structure spectroscopy and Mössbauer spectroscopy reveal a special trend of the lattice related to the diffuse dielectric phase transition as observed from dielectric data. The analysis of Raman spectra as a function of temperature reveals a peculiar behavior in the temperature region corresponding to the dielectric transition. The analysis of x-ray diffraction patterns points out a pseudocubic structure throughout the temperature range while the volume exhibits a negative thermal expansion in the region of broad dielectric maximum. Our results suggest structural modifications occurring in the system throughout a wide temperature range, interestingly, associated with changes in macroscopic properties of relaxors such as dispersion in dielectric constants and raising of dipole moments.

ACS Style

Akash Surampalli; Irene Schiesaro; Pietro Corsi; Carlo Meneghini; V. G. Sathe; Archna Sagdeo; A. K. Sinha; Giuliana Aquilanti; Edmund Welter; V. Raghavendra Reddy. Evidence of structural modifications in the region around the broad dielectric maxima in the 30% Sn-doped barium titanate relaxor. Physical Review B 2019, 100, 134104 .

AMA Style

Akash Surampalli, Irene Schiesaro, Pietro Corsi, Carlo Meneghini, V. G. Sathe, Archna Sagdeo, A. K. Sinha, Giuliana Aquilanti, Edmund Welter, V. Raghavendra Reddy. Evidence of structural modifications in the region around the broad dielectric maxima in the 30% Sn-doped barium titanate relaxor. Physical Review B. 2019; 100 (13):134104.

Chicago/Turabian Style

Akash Surampalli; Irene Schiesaro; Pietro Corsi; Carlo Meneghini; V. G. Sathe; Archna Sagdeo; A. K. Sinha; Giuliana Aquilanti; Edmund Welter; V. Raghavendra Reddy. 2019. "Evidence of structural modifications in the region around the broad dielectric maxima in the 30% Sn-doped barium titanate relaxor." Physical Review B 100, no. 13: 134104.

Accepted manuscript
Published: 01 September 2019 in Materials Research Express
Reads 0
Downloads 0

We combined x-ray powder diffraction (XRD) and x-ray absorption fine structure spectroscopy (XAFS) to characterize the crystallographic and local atomic structure of nanosized La3+ substituted CoFe2O4 spinel ferrite of composition CoLa0.15Fe1.85O4 synthesized by different synthesis routes: standard ceramic technique, citric acid (citrate) precursor and urea assisted flash auto-combustion process. Rietveld refinement of XRD patterns allowed to describe the long-range atomic structure that was used as structural model for quantitative analysis of XAFS spectra collected at the Fe-K, Co-K and La-L3 and refined via a multi-edge approach, which provided details about local atomic structure and coordination chemistry around the absorbers. Combining the complementary information from XRD and XAFS it was possible to reliably describe the cation distribution over the two spinel sublattices (tetrahedral and octahedral) as a function of the synthesis routes. We demonstrated that the inversion parameter, the cation distribution, and the local atomic structure depend strongly on the synthesis method which in particular affects the La3+ lattice-site and vacancies. In particular the citrate synthesis appears to provide a pure single pure phase with highest coordination number of La and lowest inversion parameter.

ACS Style

Neama Imam; Giuliana Aquilanti; Salwa Mansour; Zein K Heiba; Carlo Meneghini. Probing the local atomic structure in CoLa0.15Fe1.85O4 as a function of the synthesis method by multi edge XAFS. Materials Research Express 2019, 6, 115502 .

AMA Style

Neama Imam, Giuliana Aquilanti, Salwa Mansour, Zein K Heiba, Carlo Meneghini. Probing the local atomic structure in CoLa0.15Fe1.85O4 as a function of the synthesis method by multi edge XAFS. Materials Research Express. 2019; 6 (11):115502.

Chicago/Turabian Style

Neama Imam; Giuliana Aquilanti; Salwa Mansour; Zein K Heiba; Carlo Meneghini. 2019. "Probing the local atomic structure in CoLa0.15Fe1.85O4 as a function of the synthesis method by multi edge XAFS." Materials Research Express 6, no. 11: 115502.

Article
Published: 22 August 2019 in Physical Review B
Reads 0
Downloads 0

Spin-orbit coupling (SOC) plays a crucial role in magnetic and electronic properties of 5d iridates. In this paper we have experimentally investigated the structural and physical properties of a series of Ir-based double perovskite compounds Pr2−xSrxMgIrO6(x = 0, 0.5, 1; hereafter abbreviated as PMIO, PSMIO1505, and PSMIO). Interestingly, these compounds have recently been proposed to undergo a transition from the spin-orbit-coupled Mott insulating phase at x=0 to the elusive half-metallic antiferromagnetic (HMAFM) state with Sr doping at x=1. However, our detailed magnetic and electrical measurements refute any kind of HMAFM possibility in either of the doped samples. In addition, we establish that within these Pr2−xSrxMgIrO6 double perovskites, changes in Ir-oxidation states (4+ for PMIO to 5+ for PSMIO via mixed 4+/5+ for PSMIO1505) lead to markedly different magnetic behaviors. While SOC on Ir is at the root of the observed insulating behaviors for all three samples, the correlated magnetic properties of these three compounds develop entirely due to the contribution from local Ir moments. Additionally, the magnetic Pr3+ (4f2) ions, instead of showing any kind of ordering, only contribute to the total paramagnetic moment. It is seen that the PrSrMgIrO6 sample does not order down to 2 K despite antiferromagnetic interactions. But, the d5 iridate Pr2MgIrO6 shows a sharp antiferromagnetic (AFM) transition at around 14 K, and in the mixed valent Pr1.5Sr0.5MgIrO6 sample the AFM transition is shifted to a much lower temperature (∼6 K) due to weakening of the AFM exchange.

ACS Style

Abhisek Bandyopadhyay; Ilaria Carlomagno; Laura Simonelli; M. Moretti Sala; A. Efimenko; Carlo Meneghini; Sugata Ray. Evolution of electronic and magnetic properties in a series of iridate double perovskites Pr2−xSrxMgIrO6 (x=0,0.5,1.0). Physical Review B 2019, 100, 064416 .

AMA Style

Abhisek Bandyopadhyay, Ilaria Carlomagno, Laura Simonelli, M. Moretti Sala, A. Efimenko, Carlo Meneghini, Sugata Ray. Evolution of electronic and magnetic properties in a series of iridate double perovskites Pr2−xSrxMgIrO6 (x=0,0.5,1.0). Physical Review B. 2019; 100 (6):064416.

Chicago/Turabian Style

Abhisek Bandyopadhyay; Ilaria Carlomagno; Laura Simonelli; M. Moretti Sala; A. Efimenko; Carlo Meneghini; Sugata Ray. 2019. "Evolution of electronic and magnetic properties in a series of iridate double perovskites Pr2−xSrxMgIrO6 (x=0,0.5,1.0)." Physical Review B 100, no. 6: 064416.

Journal article
Published: 24 July 2019 in Applied Sciences
Reads 0
Downloads 0

The focus of this work is on the relationship between the quantitative structural characterization of bimetallic Au-Pd nanoparticles dispersed in an amorphous polymer matrix and their catalytic activity in the direct synthesis of hydrogen peroxide (DS reaction). Resonant X-ray powder diffraction with synchrotron radiation was employed to probe selectively and to reveal fine details of the structure of bimetallic nanoparticles embedded in the support. The semi-quantitative analysis of the resonant X-ray powdered diffraction data, made on a large number of metal nanoparticles, shows that in one of the polymer-supported Au-Pd catalyst for the DS reaction (P75) featured by an overall molar Pd/Au of about 5.54, the smallest metal nanoparticles (MNPs), which account for more than 99.9% of the total MNPs number and for more than 95% of the metal surface, are formed by practically pure palladium. The relative number of bimetallic alloyed nanoparticles is very small (less than 4 × 102 ppm) and they contribute to only about 2% of the total metal surface. In a second gold-enriched catalyst (P50) with an overall molar Pd/Au of 1.84, the proportion of the bimetallic alloyed nanoparticles increased to about 97% and they account for about 99% of the metal surface. As a result of the metal intermixing, the catalytic productivity for the DS reaction increased from 97 to 109 mmolH2O2/molH2, owing to the gold-promotion of palladium.

ACS Style

Paolo Centomo; Patrizia Canton; Claudio Burato; Carlo Meneghini; Marco Zecca. Resonant-XRD Characterization of Nanoalloyed Au-Pd Catalysts for the Direct Synthesis of H2O2: Quantitative Analysis of Size Dependent Composition of the Nanoparticles †. Applied Sciences 2019, 9, 2959 .

AMA Style

Paolo Centomo, Patrizia Canton, Claudio Burato, Carlo Meneghini, Marco Zecca. Resonant-XRD Characterization of Nanoalloyed Au-Pd Catalysts for the Direct Synthesis of H2O2: Quantitative Analysis of Size Dependent Composition of the Nanoparticles †. Applied Sciences. 2019; 9 (15):2959.

Chicago/Turabian Style

Paolo Centomo; Patrizia Canton; Claudio Burato; Carlo Meneghini; Marco Zecca. 2019. "Resonant-XRD Characterization of Nanoalloyed Au-Pd Catalysts for the Direct Synthesis of H2O2: Quantitative Analysis of Size Dependent Composition of the Nanoparticles †." Applied Sciences 9, no. 15: 2959.