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We present here a small-scale liquid Helium (LHe) immersion cryostat with an innovative optical setup suitable to work in long wavelength radiation ranges and under applied magnetic field. The cryostat is a multi stage device with several shielding in addition to several optical stages. The system has been designed with an external liquid Nitrogen boiler to reduce the liquid bubbling. The optical and mechanical properties of the optical elements were calculated and optimized for the designed configuration while the optical layout has been simulated and optimized among different configurations based on the geometry of the device. The final design has been optimized for low noise radiation measurements of proximity junction arrays under applied magnetic field in the wavelength range $\lambda$=250-2500 $\mu$m.

An analytical approach applied to Vincenzo Pasqualoni's wall paintings in the apse of S. Nicola in Carcere (Rome) is described in this work. The diagnostic campaign was guided following the indications of the restorers, which were supported over all the phases of the restoration, addressing the multi-analytical approach to identify the original pigments palette used by artist, the conservation state and the presence of consolidants materials, by using spectroscopic techniques supported by chemometric analyses. In particular, reflectance spectroscopy from ultraviolet to short wavelength infrared (UV-VIS-SWIR) combined with chemometric approach, X-Ray Fluorescence spectroscopy (XRF) and Raman spectroscopy are used to characterize the original pigments palette and execution techniques. In addition, original binders and synthetic compounds, used in previous restoration treatments, were detected by using Time Gated Laser Induced Fluorescence spectroscopy (TG-LIF) and Fourier Transform Infrared (FT-IR) spectroscopy. The obtained results onto the case study of S. Nicola in Carcere is a proof of a synergic integration between scientific analytical methods and conservation/restoration approach, subject of high impact and interest in the field of Cultural Heritage. Specifically, through the application of the above-mentioned techniques it was possible to identify the palette used by the artist, mainly composed of inorganic pigments such as ochers, chrome green, cobalt blue, and others. About the binders used by the artist we deduce the use of fresco technique for the upper part of the apse, combined with the use of tempera for retouches. Finally, the presence of acrylic-based compounds used in previous restoration treatments was also documented.

In the last years, significant research efforts have been devoted to the reduction of the environmental impact of biocides and to the improvement of their effectiveness over time against degradation of stone artifacts. This work reports the spectroscopic characterization of two silica nanosystems, with different geometry and structure, loaded with a biologically-active compound, the 2-mercaptobenzothiazole (MBT), for controlled antifouling release on the surface of outdoor stone artefacts. We have combined FT-IR spectroscopy in ATR mode and Raman spectroscopy to investigate the biocide loading mechanism in both nanosystems from the physical and chemical point of view. These techniques demonstrate that the geometry of confinement influences the loading of the nanoparticles and their interaction with the confining medium, with possible consequences in the biocide release rate. Moreover, we have seen that the biocide interacts with the surfactant (cetrimonium bromide, CTAB) and tends to dimerize.

The unambiguous identification of bast fibers represents one of the main challenges for archaeologists and conservators dealing with archaeological textiles, motivated by the difficulties of their investigation through the morphological features only. Therefore, in this work, a combined approach of microscopy and spectroscopy techniques is proposed. The research aims to test FT-IR spectroscopy in Attenuated Total Reflectance (ATR) mode, as a valid tool for the characterization of archaeological fibers, as already demonstrated for the modern ones, and additionally, the application of the same technique to evaluate the effect of degradation on the molecular composition of archaeological bast fibers, that may prevent their identification. To this end, a set of archeological samples, from Pompeii and the Vesuvian area, previously investigated using morphological analyses, have been studied. The results obtained showed that the preservation state of the fibres does not make their characterization simple. To understand how the ageing process influences the IR spectra of archeological fibers, a reference collection was acquired and analyzed. Moreover, two type of selected bast fibers samples were artificially aged using a climatic chamber. The outcomes achieved confirmed that the degradation process has influenced the IR spectra of the fibers to the point of making them spectrally indistinguishable, highlighting useful information to understand the role of the degradation process in the ATR FT-IR spectra of archaeological bast fibers.

An array of superconducting proximity islands has been shown to be highly tunable by electric and magnetic fields. Indeed, a small change in the electric and magnetic field can tune the system from a vortex Mott insulator to a vortex metal. This transition from localized to a non-localized state can occur as soon as the density of the superconducting vortices matches the density of the pinning sites in a non defective structure. The possibility of further modulation of non-localized superconducting states via enhancement of the superconducting order parameter or modulation of the Josephson plasma frequency is discussed. Based on the non-bolometric effects associated with the occurrence of non-equilibrium phenomena in this original superconducting networks we discuss also the possible applications of this array for a conceptually new type of radiation detector.

In this work, we address the intensity evolution of the CO2 FTIR bands of cordierite as a function of increasing T, by comparing data obtained from in situ versus quenching measurements. A natural well-characterized cordierite from Kragero (Arendal region, Norway) was studied up to 1200 °C using a heating stage fitted on a FTIR microscope. Two different oriented sections (001) and (010), respectively, were examined in order to check for the effect of the channel orientation on the CO2 release from the matrix. Spectra collected in situ show that increasing temperatures induces an increase in peak width for all CO2-related bands. The effects on the integrated absorbance A i are different for the different modes. Most notably, the integrated intensity A i of the anti-symmetric stretching mode (ν3) increases significantly up to 800 °C and then progressively decreases to 1000/1200 °C, depending on the sample orientation. Data obtained on quenched samples reveal that there is no variation in the band intensity for T

This paper describes the scientific aims and potentials as well as the preliminary technical design of RUDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity "particles factory", based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. [RIDE is also supposed to be realized in subsequent stages of development depending on the assigned priorities. (C) 2013 Elsevier B.V. All rights reserved.

We report a single-crystal Fourier-transform infrared (FTIR) study of a sample of pollucite from Maine, USA. Prior to our work, the sample had been characterized by single-crystal X-ray diffraction, neutron diffraction and electron-probe microanalysis. It is cubic Ia3d, with a crystal-chemical formula Na1.93(Cs10.48Rb0.31K0.04)Σ=10.83(Al14.45Si33.97)Σ=48.42O96·3.92H2O, and an H2O content, determined by thermogravimetric analysis, of 1.6 wt.%. The single-crystal FTIR spectrum has a doublet of intense bands at 3670 and 3589 cm–1, which are assigned to the ν3 and ν1 stretching modes of the H2O molecule, respectively. A very intense and sharp peak at 1620 cm–1 is assigned to the ν2 bending vibration. In the near-infrared region there is a relatively intense peak at 5270 cm–1, which is assigned to a combination (ν2 + ν3) mode of H2O, and a weak but well defined doublet at 7118 and 6831 cm–1, which is assigned to the first overtones of the fundamental stretching modes. A relatively weak but extremely sharp peak at 2348 cm–1 shows that the pollucite contains CO2 molecules in structural cavities. Mapping the sample using FTIR indicates that both H2O and CO2 are homogeneously distributed. Secondary ion mass spectrometry yielded an average CO2 content of 0.09±0.02 wt.%. On the basis of this value, we determined the integrated molar absorption coefficient for the spectroscopic analysis of CO2 in pollucite to be εiCO2 = 11,000±3000 l mol–1 cm–2; the linear molar absorption coefficient for the same integration range is εlCO2 = 1600±500 l mol–1 cm–1.

The capability to monitor finely the physical properties of eumelanin, an important class of biopolymers, involved in melanoma cancer pathologies, whose function and intrinsic disorder still collects the interest of many investigators, was achieved by means of electrospray deposition (ESD). By alleviating the problem of the solubility of melanin through the realization of high-quality films it was possible to spread light on the unknown biopolymer supramolecular organization. In fact, on the basis of scanning probe microscopies, electron spectroscopies, and transport properties, it was possible to delineate peculiar features of the melanin organization varying from heteropolymeric to oligomeric in character and eventually turning in a cross-linked secondary molecular structure.

FTIR microscopy with a focal plane array (FPA) of detectors enables routine chemical imaging on individual cells in only a few minutes. The brilliance of synchrotron radiation (SR) IR sources may enhance the signal obtained from such small biosamples containing small amounts of organic matter. We investigated individual cells obtained from a cell culture specifically developed for transmission FTIR imaging using either a Globar or an SR source coupled to the same instrumentation. SR-IR source focussing was optimized to control the energy distribution on the FPA of detectors. Here we show that accessing the IR absorption distribution from all the organic contents of cells at 1 x 1 microm pixel resolution was possible only with high circulating current (or = 1.2 A) illuminating a limited number of the FPA's detectors to increase the signal-to-noise ratio of IR images. Finally, a high-current SR ring is mandatory for collecting FTIR images of biosamples with a high contrast in minutes.

The presence of oxygen impurity in semiconducting materials affects the electrical properties of crystals and significantly limits their application. To remove oxygen impurity, ultra-pure hydrogen is used while growing Te-containing crystals such as CdTe, CdZnTe, and ZnTe. The hydrogenation of CdTe crystals is a technological process that purifies the basic material from oxygen, mainly cadmium and tellurium oxide compounds incorporated in CdTe crystalline lattice. In the present work we analyses the deformations induced by hydrogen and oxygen atoms in CdTe crystals looking at their influence on the near fundamental band (NFB), middle infrared (MIR) and far infrared (FIR) reflectivity spectra as well as on cathodoluminescence (CL) spectra. Comparison of the hydrogenated CdTe phonon structure profiles confirms the presence of hydrogen atoms bounded inside the lattice. The possible localization of hydrogen and oxygen ions within the tetrahedron coordinated lattice is discussed in the framework of a model that shows a good agreement with recent NFB, MIR and FIR experiments carried out on hydrogenated CdTe crystals. Measured reflection spectra in the wavelength range 190-1400 nm (NFB) indicate the appearance in CdTe(HM) and CdTe(HL) of additional maxima at 966 nm related to the electron transitions from level about 0.2 eV above the valence band. The CL spectra confirmed existence of this electron level. We present a possible H2 alignment similar to the single H model i.e., over the face (at about 0.38 A). For this model the angle from the central atom to the H atoms is equal to 64° which is also close to the bonding angle of CdH2 (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The influence of temperature on the far-infrared (FIR) spectrum of polycrystalline Ag2CdI4 has been investigated by Fourier Transform Infrared (FTIR) spectroscopy measurements. The FIR phonon spectrum has also been calculated by means of quantum mechanical density functional theory (DFT). The comparison of calculated and measured spectra allows the fast and reliable assignment of the measured phonon modes, and thus clarifies the mode splitting character obtained at elevated temperatures.

The comparative far-infrared spectroscopy studies of Rb0.8Cs0.2Cl and Rb0.8Cs0.2Cl containing CsPbCl3 nanocrystals between 170 and 320 K are reported. The effect of cesium lead chloride nanocrystals on the phonon modes of the host matrix, particularly manifested in different temperature behavior of LO–TO splitting and the temperature dependence of high frequency dielectric constant, are demonstrated.

W.M. Kwiateka,∗, C. Paluszkiewicz, A. Banaś, A. Kisiel, M. Podgorczyk, A. Marcelli, M. Cestelli Guidi and M. Piccinini Institute of Nuclear Physics, PAS, Radzikowskiego 152, 31-342 Krakow, Poland AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow, Poland INFN — Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Rome), Italy Universita’ Roma Tre, Dip. Scienze Geologiche, L. go S. Leonardo Murialdo 1, 00146 Rome, Italy

The optical conductivity of La–Ca, Nd–Sr, and Bi–Sr manganites with commensurate charge order (CO) has been first observed in the sub-THz region. Below, the ordering temperature TCO well-defined peaks are observed, associated with side bands. They are assigned to pinned phasons, and to combinations of phasons and amplitudons, respectively. In La1−n/8Can/8MnO3 with n=5, 6, one can thus determine the electron-phonon coupling, the effective mass of the CO system, and its contribution to the dielectric constant. Their values support a description of the CO in La–Ca manganites in terms of a CDW approach. In Bi0.5Sr0.5MnO3, where TCO> 500 K and the coupling is stronger, only the combination bands are clearly detected.

The influence of dilution by diamagnetic ions on the magnetic ordering in single-crystal CocMg1−cO solid solutions was studied by Raman spectroscopy and magneto-optical microscopy in a wide range of temperatures (6 < T < 200 K). Far infrared absorption measurements of antiferromagnetic resonance (AFMR) were also performed for pure CoO. It was found that the domain structure and the contribution from Brillouin zone center magnons to Raman scattering and AFMR disappear well below the Neel temperature, whose value was determined from neutron diffraction and magnetic susceptibility measurements.

The paper reports on assignment of lattice reflection spectra of the Hg1−x Znx Te alloys (x = 0.10, 0.35, and 0.55) measured in the 40–300-K temperature interval and on a comparative analysis of the lattice vibration parameters for two alloy systems, HgZnTe and HgCdTe, in the low-frequency optical vibration region (the region of the anomalous Hg-Te vibrational mode in HgTe). While the parameters of the fundamental lattice modes are closely similar, the temperature dependences of the low-frequency modes of the two alloy systems are radically different. Their thermal activation energies for the HgZnTe and HgCdTe alloys are 3.3 and 50.0 meV, respectively. The results of the experiment are treated in terms of the double-well potential model for the Hg atom in the alloy lattice.

Beam diagnostic is a fundamental constituent of any particle accelerators either dedicated to high-energy physics or to synchrotron radiation experiments. All storage rings emit radiations. Actually they are high brilliant sources of radiation: the synchrotron radiation emission covers from the infrared range to the X-ray domain with a pulsed structure depending on the temporal characteristics of the stored beam. The time structure of the emitted radiation is extremely useful as a tool to perform time-resolved experiments. However, this radiation can be also used for beam diagnostic to determine the beam stability and to measure the dimensions of the e − or e + beam. Because of the temporal structure of the synchrotron radiation to perform diagnostic, we need very fast detectors. Indeed, the detectors required for the diagnostics of the stored particle bunches at third generation synchrotron radiation sources and FEL need response times in the sub-ns and even ps range. To resolve the bunch length and detect bunch instabilities, X-ray and visible photon detectors may be used achieving response times of a few picoseconds. Recently, photon uncooled infrared devices optimized for the mid-IR range realized with HgCdTe semiconductors allowed to obtain sub-nanosecond response times. These devices can be used for fast detection of intense IRSR sources and for beam diagnostic. We present here preliminary experimental data of the pulsed synchrotron radiation emission of DAΦNE, the electron positron collider of the LNF laboratory of the INFN, performed with new uncooled IR detectors with a time resolution of a few hundreds of picoseconds.

The IR reflection spectra of structures that consist of alternating layers of CdTe quantum dots and ZnTe barriers and are grown on ZnTe and CdTe/ZnTe buffer layers on GaAs(001) substrates are studied. The spectra are processed using dispersion analysis, and the parameters of the oscillators are determined. In the spectra, quantum dots manifest themselves in the form of a broad band at a frequency close to the frequency of the Frohlich mode. It is revealed that the spectra contain features associated with the interdiffusion of the CdTe and ZnTe compounds, i.e., bands attributed to the local mode of Zn atoms in the CdTe compound and two gap modes of Cd atoms in the ZnTe compound.

An influence of ( Cd i ) n metallic clusters on the optical absorption and phonon spectra of CdI 2 crystals was studied. Metallic clusters of spherical shape were formed during the growth of non-stoichiometric crystals. Radii of clusters are in range from 10 to 500 nm according to scanning electron microscopy (SEM) data. The density of clusters was estimated from fractal dimension calculations. The fractal dimension of ( Cd i ) n clusters has been found to be varied from 1.488 to 1.793. In the framework of Mie theory the spectral and size dependencies of extinction coefficients were calculated. From the experimentally obtained spectra it is evident that the metallic clusters are responsible for the bands in the transparency region of CdI 2 crystals (360–430 nm) and for the peaks in the mid-infrared absorption spectra which are not present in the spectra of pure cadmium iodide. The nature of this additional optical and infrared absorption is concerned with the bulk and surface plasmons and the surface phonon modes of metallic clusters, respectively.

The Frascati National Laboratories (LNF) are the oldest and largest research infrastructure of INFN, mainly devoted to the research in nuclear and particle physics, to the development of particle accelerators and frontier studies on new acceleration techniques. LNF is the place where the first electron-positron collisions were obtained in the early 60s. Presently LNF operates two accelerator complexes: DAFNE, an e+e- collider with center of mass energy set to the mass of the Φ meson, 1020 MeV. SPARC, a high intensity photoinjector capable of delivering electron beams up to 200 MeV, combined with a high power laser (FLAME), able to produce ultra short pulses, in the so called SPARC_LAB facility. The laboratory hosts also the NAUTILUS gravitational waves resonant bar detector, and thanks to the availability of several infrastructures, workshops, clean rooms etc.., it is also widely used as a facility for constructing large particle detectors used in other laboratories. The purpose of the present document is to address the question: is there a viable program on the development of internal activities which can allow the Laboratory to maximally exploit its capabilities and to maintain its role at the forefront of scientific research in the next decade? In particular, given the present Italian financial situation, is this possible by wisely upgrading the presently running infrastructures at moderate costs? On November 10-11, 2014 a workshop was held at LNF with the aim to discuss the above issues, with a broad participation of researchers from Italian and foreign institutions. A second workshop dedicated to the applications of the existing facilities to Materials Science was held on February 26-27, 2015. This document tries to summarize the main conclusions of these discussions.

In the present work the deformations induced by hydrogen and oxygen atoms in CdTe crystals have been analyzed looking at their influence on the middle infrared (MIR) and far infrared (FIR) reflectivity spectra. Comparison of the hydrogenated CdTe phonon structure profiles confirms the presence of hydrogen atoms bounded inside the lattice. The possible localization of hydrogen and oxygen ions within the tetrahedron coordinated lattice is discussed in the framework of a model that shows a good agreement with recent MIR experiments carried out on hydrogenated CdTe crystals.

Tetrahedron coordinated sphalerite quaternary systems of type A 1− x B x Y y Z 1− y consist exclusively of binary and ternary elemental tetrahedra, 4 of the first and 4 of the latter, each 1 with 3 configurations, i.e., a total of 16 elemental tetrahedron configurations. These configurations cannot contain all four constituent atoms simultaneously in the same elemental tetrahedron; as a consequence we can consider each ternary tetrahedron composition as diluted in the quaternary compound. Thus, A 1− x B x Y y Z 1− y extended X-ray absorption fine structure (EXAFS) data can be treated by using the strained tetrahedron model which, originally developed to deal with ternary systems, has already exhibited excellent agreement with numerous experimental data. To determine ion site occupation preferences of quaternary systems, we applied this model to our EXAFS data for Cd 1− x Mn x Se y Te 1− y and to Ga x In 1− x As y Sb 1− y data available in the literature, and compared them to those derived from ternary data for Cd 1− x Mn x Te and Ga x In 1− x As. In both sets, as the ternary is diluted in the quaternary system, a drift of the preference values of the pure ternary is observed. The present analysis of experimental reflectivity far-infrared (FIR) phonon spectra of quaternary Cd 1− x Mn x Se y Te 1− y crystals confirms the model predictions and leads to an interpretation of the experimental data for A 1− x B x Y y Z 1− y quaternary systems.

This work presents result of far-infrared spectra obtained (by synchrotron radiation as well as by the mercury lamp) from samples ZnxCd1−xTe (x = 0.056, 0.11, 0.16, 0.22, 0.28, 0.7). The results are obtained from two different polarizations for planes (1 1 1) and (1 1 0). The interpretation of this result is based on the model of five tetrahedron cells.

We investigated different AlN nano-systems using spectroscopic methods. Experiments were performed at the Synchrotron Radiation Facility of the Laboratori Nazionali di Frascati using both XANES (x-ray absorption near edge spectroscopy) and FTIR (Fourier transform infrared spectroscopy) techniques in order to investigate materials with both interesting tribological and electronic properties. Comparisons have been performed between measurements by standard x-ray diffraction (XRD) and x-ray absorption (XRS) at the K-edge of Al, a spectroscopy method sensitive to the local order and correlated to the local and empty density of states of this wide band-gap semiconductor. Preliminary XAS simulations at the Al K edge are also presented. Correlations between XRD and XAS have been drawn, since x-ray absorption reveals structural information complementary to that addressed by x-ray diffraction. Moreover, a comparison has been performed by infrared (IR) absorption both in the mid- and in the far-IR ranges between different AlN forms: namely, powders, nanoparticles and nanotubes. Data clearly show changes connected with the electronic properties and the optical phonon modes of AlN nano-systems.

The narrow-gap II-VI and IV-VI alloys are convenient objects for studying the electron-phonon interaction. However, the concentration of free carriers in the IV-VI alloys is rather high (∼1018 cm−3), which complicates studying this effect, by the optical reflection method. The concentration of free carriers in the narrow-gap Hg1-xZnxTe alloys is considerably lower (∼1016 cm−3). Therefore, the plasma component exerts less effect on the lattice reflection spectrum. The reflection spectra of Hg1-xZnxTe crystals with x = 0.1–1 were studied in the far-IR region in the range of 30–700 cm−1 at 40–300 K. Using the dispersion analysis and the Kramers-Kronig method, the frequencies of the TO phonons of the HgTe-like and ZnTe-like modes were determined depending on the composition. It is shown that the reconstructed phonon spectrum involves two modes. The temperature dependences of the frequencies of the TO phonons and the damping parameter were measured for the narrow-gap alloy with x = 0.1 in the range of 80–200 K. A decrease in the frequency of the TO phonon of the soft mode in the vicinity of the inversion point of the bands at T = 110 K was for the first time found by optical methods. The damping parameter slightly increases in the vicinity of this temperature. The result obtained qualitatively agreed with the theoretical model of Kawamura et al., which makes allowance for the effect of the electron-phonon interaction on the frequency of the soft mode in the IV-VI compounds.

1 was studied in polycrystalline Ni c Mg 1-c O solid solutions with c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60. The composition and temperature dependences of the absorption suggest that the band has magnetic origin re- lated to simultaneous excitation of two-magnons at the Brillouin-zone boundary and one phonon. -1 in polycrystalline NicMg1-cO solid solutions. Polycrystalline solid solutions NicMg1-cO (c=0.99, 0.98, 0.97, 0.95, 0.90, 0.80, 0.70 and 0.60) were prepared using ceramic technology from the appropriate amounts of aqueous solutions of Mg(NO3)2·6H2O and Ni(NO3)2·6H2O salts, which were mixed and slowly evaporated. The remaining dry 'flakes' were heated up to 500-600 oC to remove NO2 completely. The obtained polycrystalline solid solutions were pressed and annealed during 100 hours at 1200 oC in air and then rapidly cooled down to room temperature. The pure polycrystalline NiO and MgO were obtained using the same method by thermal decomposition of the above mentioned salts. These NicMg1-cO solid solutions have greenish

First results from the SINBAD beam line at DAΦNE are reported. The SR brilliance, as measured in the far infrared at the sample position, has been compared with the one of the mercury lamp. For λ =100 μm and through an aperture of 1 mm, the gain in intensity is larger than 20. The high brilliance of the synchrotron radiation in the far-infrared is fully exploited by high-pressure experiments. Preliminary experiments with a diamond-anvil cell in the 10 GPa range are reported.

The optical reflectivity in the far infrared region (FIR spectra) was measured for five samples of ZnxCd1−xTe in the Zn range 0.056

This paper reports on water speciation and diffusion in synthetic beryl samples treated in CO2-rich atmosphere, at 700 MPa and 700 and 800 °C, respectively. The study has been conducted by means of polarized FTIR (Fourier transform infrared) integrated with FPA (focal plane array) imaging. As expected, the infrared spectra show the presence of CO2 but also of minor H2O interpreted as resulting from moisture present in the starting materials used for the experiments. FPA-FTIR images show that H2O diffuses into the beryl matrix along the structural channels oriented parallel to [001]. Spectra collected along profiles parallel to the c-axis show subtle changes as a function of the distance from the crystal edge; these changes can be correlated to a progressive change in the H2O coordination environment in the channel, as a response to the varying H2O/alkali ratio. In particular, the data show that when 2H2O > Na+ apfu (atoms per formula unit), H2O can assume both type I and type II orientation; in the latter case, each Na cation coordinates two H2O[II] molecules (doubly coordinated H2O). If 2H2O

We report on an 55 Mn NMR investigation of calcium-doped manganite samples carried out at 4.2 K. In the insulating members of the family, the localization of hole-rich ferromagnetic clusters is revealed by the peculiar two-peaked spectra, and by distinct shifts of the resonance lines in an external field. Results are discussed in view of inelastic neutron scattering findings and combined 139 La NMR and μSR data.

We present a study performed on several LaMnO3+x/2 compositions. Detailed analysis around x=0.09 detects phase separation between a higher transition, Tc, and a lower one TN, with coexisting fluctuating and magnetically ordered clusters (the Neel point, TN, being the onset of an inhomogeneous non-collinear antiferromagnetic order detected by neutrons). The ordered clusters give rise to an extremely fast, static Kubo–Toyabe muon depolarization, while mixed static and dynamic local fields are detected inside the fluctuating clusters. Below TN precession frequency lines are resolved, despite the huge broadening introduced by localized Mn4+ ordered moments. A phase diagram is obtained and briefly discussed in the context of electronic phase separation.

Low-dose exposure of ionizing radiation triggers cell-to-cell communications and tissue interplay alterations. These alterations may play a fundamental role in non-cancer effects, overwhelming the theory of the DNA centric approach. Neither the mechanisms of these effects are fully understood nor is it possible to dissect the real incidence of quality and quantity of incident radiation during in vivo exposure, overall for particulate high-linear energy transfer (LET) radiation. Moreover, the knowledge of particulate high-LET radiation is mandatory for the human deep space exploration and to gain efficiency in the dose/effect ratio for radiotherapy. The aim of this minireview was to describe an integrated system approach to the radiation biology of cosmic interest which could be set up in the framework of a future Sino-Italy cooperation among participating laboratories. We propose, in particular, to deliver X-rays and neutron irradiation at ENEAFNG (Frascati, Italy) and heavy ion irradiation at IMPCAS (Lanzhou, China) to in vivo models. The integrated system approach will focus on the correlation between the quality and quantity of radiation exposure and its in vivo biological effects. Wide range molecular profiling will analyze mainly cell and DNA damages and cell-to-cell and tissues interplay, meanwhile biochemical and chemical specific composition will be detected by infrared spectroscopy. The recently characterized alteration of leptin metabolism is discussed in more detail to present a successful example of systemic approach to cosmic radiation biology. ﾩ Accademia Nazionale dei Lincei 2013.

This paper relates an infrared (IR) (6000–2500; 1400–400 cm–1) spectroscopic study of sideronatrite, Na2Fe3+(SO4)2(OH)·3H2O. Spectra in the 600–1250 cm–1 range are dominated by fundamental S–O absorption bands. Factor-group analysis based on the space group P212121(D42) is in accordance with the observed band multiplicity. A broad and convolute absorption centred around 3400 cm–1 and a sharp band at 3605 cm–1 are observed in the 2900–3900 cm–1 frequency region. The resolution of the broad band is significantly improved at liquid nitrogen temperature; seven components can be fitted to the pattern and these can be assigned to H2O/OH molecules in the structure. All components in the broad band and the sharp absorption at 3605 cm–1 are strongly polarized for E//a, in accordance with the structure analysis results. Infrared transmission spectroscopy is a useful tool to identify these sulfate minerals occurring in specific geological environments.

Diagnostics is a fundamental issue for accelerators whose demands are continuously increasing. In particular bunch-by-bunch diagnostics is a key challenge for the latest generation of lepton colliders and storage rings. The Frascati Φ-factory, DAΦNE, colliding at 1.02 GeV in the centre of mass, hosts in the main rings few synchrotron radiation beamlines and two of them collect the synchrotron radiation infrared emission: SINBAD from the electron ring and 3+L from the positron ring. At DAΦNE each bucket is 2.7 ns long and particles are gathered in bunches emitting pulsed IR radiation, whose intensity in the long wavelength regime is directly proportional to the accumulated particles. Compact uncooled photoconductive HgCdTe detectors have been tested in both beamlines using dedicated optical layouts. Actually, the fast rise time of HgCdTe semiconductors give us the chance to test bunch-by-bunch devices for both longitudinal and transverse diagnostics. For the longitudinal case, single pixel detectors have been used, while for the transverse diagnostics, multi-pixel array detectors, with special custom design, are under test. This contribution will briefly describe the status of the research on fast IR detectors at DAΦNE, the results obtained and possible foreseen developments.

Cosmic dust grains (CD) are part of the evolution of stars and planetary systems and pervade the interstellar medium. Thus, their spectral signature may be used to deduce the physical features of the observed astronomical objects or to study many physical and chemical processes in the interstellar medium. However, CD samples are available only from sample-and-return space missions. Thus, they are rare and not sufficient to be used to perform laboratory experiments of astrophysical interest, such as to produce reference spectra. In this contribution, we describe a new physical vapor deposition (PVD) technique that allows the production of amorphous samples with controlled chemical and morphological characteristics. In particular, this technique was developed to grow uniform or microstructured layers of Mg-Fe amorphous silicates (olivine or pyroxene) that are materials of wide interest for laboratory experiments. We discuss the first results that were achieved by applying this new synthesis method. The layers were studied by combining infrared spectroscopy, scanning electron microscopy, and X-ray spectroscopy. The X-ray microscopy was used for the first time to characterize the internal structure of the grains in these synthetic samples. Finally, future improvements of the technique and foreseen applications are discussed.

Two beamlines for the use of InfraRed Synchrotron Radiation (IRSR) are presently working in Italy, at the ELETTRA storage ring in Trieste, and at the collider DAFNE in Frascati. A third facility, SPARC in Frascati, has been equipped for the extraction of Terahertz radiation with the aim to perform pump-probe time-domain experiments. Here we describe those apparata and we review the main results that the Italian groups have obtained therein, in recent years, in solid-state physics. We also describe the experiments performed in collaboration with the storage ring BESSY in Berlin, for the exploitation of Coherent Synchrotron Radiation, and the terahertz beam line recently implemented at SPARC, the Free Electron Laser of Laboratori Nazionali di Frascati

This paper discusses gene expression changes in the skin of mice treated by monoenergetic 14 MeV neutron irradiation and the possibility of monitoring the resultant lipid depletion (cross-validated by functional genomic analysis) as a marker of radiation exposure by high-resolution FT-IR (Fourier transform infrared) imaging spectroscopy. The irradiation was performed at the ENEA Frascati Neutron Generator (FNG), which is specifically dedicated to biological samples. FNG is a linear electrostatic accelerator that produces up to 1.0 × 10(11) 14-MeV neutrons per second via the D-T nuclear reaction. The functional genomic approach was applied to four animals for each experimental condition (unirradiated, 0.2 Gy irradiation, or 1 Gy irradiation) 6 hours or 24 hours after exposure. Coregulation of a subclass of keratin and keratin-associated protein genes that are physically clustered in the mouse genome and functionally related to skin and hair follicle proliferation and differentiation was observed. Most of these genes are transiently upregulated at 6 h after the delivery of the lower dose delivered, and drastically downregulated at 24 h after the delivery of the dose of 1 Gy. In contrast, the gene coding for the leptin protein was consistently upregulated upon irradiation with both doses. Leptin is a key protein that regulates lipid accumulation in tissues, and its absence provokes obesity. The tissue analysis was performed by monitoring the accumulation and the distribution of skin lipids using FT-IR imaging spectroscopy. The overall picture indicates the differential modulation of key genes during epidermis homeostasis that leads to the activation of a self-renewal process at low doses of irradiation.

Fourier-transform infrared (FTIR) imaging has been used to investigate brain tumor angiogenesis using a mice solid tumor model and bare-gold (∅ 25 nm) or BaSO4 (∅ 500 nm) nanoparticles (NP) injected into blood vasculature. FTIR images of 20-μm-thick tissue sections were used for chemical histology of healthy and tumor areas. Distribution of BaSO4-NP (using the 1,218–1,159 cm−1 spectral interval) revealed clearly all details of blood vasculature with morphological abnormalities of tumor capillaries, while Au-NP (using the 1,046–1,002 cm−1 spectral interval) revealed also diffusion properties of leaky blood vessels. Diffusion of Au-NP out of vascular space reached 64 ± 29 μm, showing the fenestration of “leaky” tumor blood vessels, which should allow small NP (

Similar ternary semiconductors are sometimes associated with widely different structures characterized by different site occupation preferences. We have used far-infrared (FIR) spectra to determine the site occupation preference coefficients for three ternary semiconductor alloys: ZnCdTe, ZnHgTe and CdHgTe and, in the case of ZnHgTe, have validated it by X-ray absorption fine structure (EXAFS) analysis. While ZnCdTe spectra exhibit the canonical configuration with eight phonon lines free of vibrational defect lines and only a slight departure from a random ion distribution, CdHgTe spectra show the eight canonical phonon modes plus an additional vibrational defect line and constant preference coefficients. In contrast, two defect lines and only four modes characterize ZnHgTe spectra, as extreme preferences prevent the formation of two of the five expected tetrahedral configuration arrangements. Moreover, for this system, comparison with EXAFS data points out the vibrational nature of both the extra lines. The analysis clearly shows that assuming a Bernoulli distribution of the component configurations of semiconductors may lead to wrong assessments of the evolution of its properties with relative content., JRC.D.5-Standards for Food Bioscience

In this paper we describe recent applications of micro-infrared imaging in the Earth sciences. We address, in particular, the use of Fourier-transform infrared (FTIR) spectroscopy in characterizing the zoning and speciation of H and C in a variety of geological materials, including microporous minerals, nominally anhydrous volcanic minerals (NAMs), and crystal inclusions. These investigations show that use of the modern techniques of FTIR imaging enables detection of the zoning of volatile species across the studied samples, and possible configuration changes of structurally-bound carbon molecular species (e.g., CO(2) vs CO(3)) during crystal growth. Such features, which are not accessible with other micro-analytical techniques, may provide information about the physicochemical properties which act as constraints in the genesis of the samples, and important information about the evolution of the geological system. Tests performed with focal-plane-array detectors (FPA) show that resolution close to the diffraction limit can be achieved if the amounts of the target molecules in the sample are substantially different. We also point out the possibility of using FTIR imaging for investigations under non-ambient conditions.

High-pressure (P) Raman $(0\ensuremath{\le}\text{P}\ensuremath{\le}12\text{ }\text{GPa})$ and Infrared $(0\ensuremath{\le}\text{P}\ensuremath{\le}24\text{ }\text{GPa})$ spectra are collected on two samples of the ${\text{LaMn}}_{1\ensuremath{-}x}{\text{Ga}}_{x}{\text{O}}_{3}$ series: $x=0.2$ and 0.6 with cooperative Jahn-Teller distorted and regular ${\text{MnO}}_{6}$ octahedra, respectively. Raman spectra are also collected at $\text{P}=0$ on varying Ga-content $(0\ensuremath{\le}x\ensuremath{\le}0.8)$. A remarkable octahedral symmetrization is observed on increasing P in the $x=0.2$ sample, as well as $x$ at $\text{P}=0$. The $x$-driven symmetrization process is homogeneous whereas, compressing the lattice, a phase-separated regime (regular/distorted ${\text{MnO}}_{6}$) is observed at intermediate P. The comparison between the spectra of the two samples in the high-pressure regime strongly suggests the presence of small residual distortion in the $x=0.2$ even at the highest P. Infrared data show that P is effective only in the $x=0.2$ sample (P-driven band-gap filling) suggesting the relevance of orbital and magnetic order on the metallization process. Our results provide a unique experimental base to clarify the origin of the peculiar pressure behavior of the parent ${\text{LaMnO}}_{3}$.

In a metallic manganite, the substitution of ${\mathrm{Mn}}^{+3}$ by ${\mathrm{Ga}}^{+3}$ locally destroys both the ferromagnetic order and the Jahn--Teller distortion, without heavily affecting the crystal structure. One can thus observe an unusual metal-to-insulator transition, which is induced neither by the temperature nor by changes in the divalent-ion doping. This transition is studied here by comparing the infrared reflectivity of five samples of ${\mathrm{La}}_{2∕3}{\mathrm{Sr}}_{1∕3}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}{\mathrm{O}}_{3}$, with $x$ increasing from 0 to 0.30. The dramatic effect of Ga on the transport properties is monitored through the decrease in the number of free carriers and the increase in their effective mass, until a good metal such as ${\mathrm{La}}_{2∕3}{\mathrm{Sr}}_{1∕3}\mathrm{Mn}{\mathrm{O}}_{3}$ is turned into an insulator at all temperatures. A simple model which links the measured optical parameters to the magnetization $M(x,T)$ well describes the behavior of the plasma frequency, the scattering rate, and the midinfrared absorption, throughout the Ga-induced metal-to-insulator transition.

The phonon spectrum of CdTe hydrogenated to various degrees is interpreted according to the original model, which takes into account the abundances of all naturally occurring Cd and Te stable isotopes and considers only five independent parameters to describe the 'bulk-isotope effect' line shape. The least square fitting (LSqF), unfolds the experimental data, obtained at different temperatures. The LSqF of the phonon line also considers the presence of additional oscillator contributions that we assign to vacancies or to lattice deformations occurring in the crystal.

In the optical conductivity of four different manganites with commensurate charge order (CO), strong peaks appear in the meV range below the ordering temperature T_{CO}. They are similar to those reported for one-dimensional charge density waves (CDW) and are assigned to pinned phasons. The peaks and their overtones allow one to obtain, for La{1-n/8}Ca{n/8}$MnO{3} with n = 5, 6, the electron-phonon coupling, the effective mass of the CO system, and its contribution to the dielectric constant. These results support a description of the CO in La-Ca manganites in terms of moderately weak-coupling and of the CDW theory., Comment: To be published on Phys. Rev. Lett

We report on Raman measurements carried out on Ca 2 FeMoO 6 and Sr 2 FeMoO 6 double perovskites as functions of pressure (0-15 GPa) and of temperature (298-370 K). The Raman spectrum of both the samples is characterized by a phonon peak at ~460 cm −1 whose large asymmetric profile is ascribed to a Fano resonance. The careful data analysis provides in particular the Fano asymmetry parameter q which results to be nearly independent from pressure and temperature, thus suggesting a remarkable stability of both charge-carrier density and charge-lattice coupling. Finally, our data allow us to ascribe the conductivity transition previously observed around 2 GPa in Sr 2 FeMoO 6 not to an intrinsic property but to the pressure-induced opening of intergrain percolation paths.