Elisa Pannunzio miner

• Ph.D.
• National University of Córdoba

The formation of the crystalline organic polymer (OP) islands on top of double perovskite ferromagnetic La2Ni1–xMn1+xO6 (x=0.4) thin films by RF sputtering is reported. The presence of randomly ramified organic polymer islands for film grown on top of SrTiO3 and LaAlO3 substrates suggest the fractal growth. The stability of fractal OP islands is te...

Mineralogy and geochemistry of pegmatites from the Pocho group, Altautina District (Córdoba). Granitic pegmatites belonging to the Pocho Group (western Córdoba Province) are lens-shaped, deformed zoned bodies that are hosted by paragneisses and migmatites of the Piedras Rosadas Complex. Major minerals are those typical for granitic pegmatites (quar...

In this work we report on the epitaxial growth of La2NiMnO6 double perovskite thin films on top of (001) oriented SrTiO3 substrates by RF magnetron sputtering. The influence of oxygen pressure (PO2) and growth temperature on the microstructure, stoichiometry of the films and magnetic and transport properties is thoroughly investigated. It is found...

Mechanical control of electrical properties in complex heterostructures, consisting of magnetic $\mathrm{FeO_x}$ nanoparticles on top of manganite films, is achieved using the atomic force microscope (AFM) based methods. Under applied pressure by AFM tip, the drop of the electrical conductivity is observed inducing an electrically insulating state...

The development of a novel adsorbent based on Sn(II) oxy-hydroxide nanoparticles and the optimization of main synthesis parameters was examined for the efficient removal of hexavalent chromium at low residual concentration levels. The aqueous hydrolysis of Sn(II) salts in a continuous-flow process was evaluated as an effective method to synthesize...

Two spinel-type oxides, CuMn2O4 and CoMn2O4 were synthesized by a simple combustion method. The oxides were characterized by X-ray Diffraction, infrared spectroscopy, scanning electron microscopy and atomic absorption spectroscopy. The structures of the obtained oxides were refined by the Rietveld method. The obtained samples were tested in the cat...

We report for the first time a green, simple, and low-cost synthesis of silver nanoparticles (AgNPs) by mixing AgNO3 solution with the aqueous leaf extract of Belgian endive, a variety of Cichorium intybus L., without any harmful reducing and capping agents. The biosynthesis of AgNPs was observed by the color charge from colorless (metal salt solut...

X-ray absorption spectroscopy was used to determine the valence state in La$_2$Co$_{1-x}$Mn$_{1+x}$O$_6$ ($x\approx 0.23$) thin films. We found that in spite of the non-stoichiometry, Co is in a divalent state while Mn ions show a mixed valence state. The relation of this finding with the magnetic properties of the films is discussed. X-ray magneti...

RCrMnO5 (R = Sm, Eu, Gd, Tb, Ho, and Er) were synthesized at high O2 pressures and 900–950 °C. Crystal structures were refined by using powder X-ray diffraction (PXRD) and powder neutron diffraction (PND) for Tb, Ho, and Er compounds and PXRD for Sm, Eu and Gd compounds. All compounds were isostructural with RMn2O5. By using the bond-valence model...

Pyrochlores of the RE2FeSbO7type were synthesized by ball-milling followed by annealing in free atmosphere at high temperatures. The samples prepared were characterized by X-ray diffraction, Raman spectroscopy and 57Fe Mössbauer spectroscopy, at room temperature. The results showed that RE2FeSbO7compounds have a cubic structure, i.e., Fd-3m (#227)...

Pyrochlores of the RE2FeSbO7 type were synthesized by ball-milling followed by annealing in free atmosphere at high temperatures. The samples prepared were characterized by X-ray diffraction, Raman spectroscopy and ⁵⁷Fe Mössbauer spectroscopy, at room temperature. The results showed that RE2FeSbO7 compounds have a cubic structure, i.e., Fd-3m (#227...

Secondary jarosite and water-soluble iron-sulfate minerals control the composition of acid mine waters formed by the oxidation of sulfide in tailings impoundments at the (Zn-Pb-Ag) Pan de Azúcar mine located in the Pozuelos Lagoon Basin (semi-arid climate) in Northwest (NW) Argentina. In the primary zone of the tailings (9.5 wt % pyrite-marcasite)...

The crystal structure of sarmientite, Fe3+2(AsO4)(SO4)(OH)·5H2O, from the type locality (Santa Elena mine, San Juan Province, Argentina), was solved and refined from in-house powder diffraction data (CuKα1,2 radiation). It is monoclinic, space group P21/n, with unit-cell dimensions a = 6.5298(1), b = 18.5228(4), c = 9.6344(3) Å, β = 97.444(2)°, V =...

Oxidation states of transition metal cations in spinels-type oxides are sometimes extremely difficult to determine by conventional spectroscopic methods. One of the most complex cases occurs when there are different cations, each one with several possible oxidation states, as in the case of the magnetoresistant Mn(2-x)V(1+x)O4 (x=0,1/3 and 1) spine...

Perovskites LnV0.5Fe0.5O3 (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er) were synthesized by rapid solidification from arc-melted samples and characterized by the study of their crystal structure and hyperfine properties. These metastable solid solutions crystallized in the Pbnm symmetry, with the iron and vanadium cations randomly distrib...

The samples Bi2BB′O7, with B=Cr and Fe and B′=Nb, Ta and Sb were prepared by solid state method. The crystallographic structure was investigated on the basis of X-ray powder diffraction data. Rietveld refinements show that the crystal structure is cubic, space group Fd-3m. The Bi3+ cation on the eight-coordinate pyrochlore A-site shows displacive d...

Sanjuanite, Al-2(PO4)(SO4)(OH)center dot 9H(2)O, is a microcrystalline fibrous mineral found in Pennsylvanian slates belonging to the Los Jejenes Formation at the Pocito Department, San Juan Province, Argentina. Sanjuanite is monoclinic, space group P2(1)/n, with unit-cell dimensions a 13.9163(5), b 17.2422(5), c 6.1125(3) angstrom, beta 98.255(4)d...

High-resolution Kβ spectra of Cr oxide were measured using a non-conventional spectrometer. Theoretical spectra were obtained using the DV-Xα method in order to interpret the Kβ spectrum structures. Kβ spectrum structures were analyzed and spectral parameters show a great sensitivity to the oxidation state and to the Cr–O distance. High-purity samp...

Pyrochlore-related compounds of the R2FeTaO7 type (with R=Gd , Eu, Dy, and Y) were synthesized by solid-state reaction of precursor oxides. The compounds were structurally and magnetically characterized by x-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The results revealed that this subfamily of pyrochlores crystallizes with...

Pyrochlore-related compounds of the R 2 FeTaO 7 type with R = Gd, Eu, Dy, and Y were synthesized by solid-state reaction of precursor oxides. The compounds were structurally and magnetically characterized by x-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. The results revealed that this subfam-ily of pyrochlores crystallizes wi...

The new double perovskite La3Co2TaO9 has been prepared by a solid-state procedure. The crystal and magnetic structures have been studied from X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD) data. Rietveld refinements were performed in the monoclinic space group P21/n. The structure consists of an ordered array of alternating B′...

A synthetic analogue, Ca(Ti0.6Al0.2Sb0.2)OSiO4, of antimony-bearing titanite of a composition similar to that found at St. Marcel-Praborna (Italy) was synthesized using ceramic methods and the crystal structure was refined using the Rietveld method. Unit-cell dimensions (in Å) are a=7.0184(1), b=8.7097(2), c=6.5586(1), and β=113.700(1)°. The substi...

We present experimental results of electrical resistivity (ρ) , magnetoresistance (MR), Seebeck coefficient (S) , and magnetic susceptibility (χ) experiments at high temperature on the spinel Mn _2-x V _1+x O ₄ series with x=0 , 1 3 , and 1, prepared by solid state reaction. The Rietveld analysis of neutron powder dif...

We synthesized the spinel-type compounds belonging to the Mn2−xV1+xO4 series with x = 0, 1/3 and 1 as polycrystalline powders. Crystal and magnetic structures were refined using synchrotron X-ray and neutron powder diffraction. At 300 K all members crystallize in the cubic system, space group Fd 3¯m, and show a structural transition at low temperat...

The El Portezuelo Granite (Catamarca Province, NW Argentina), probably of Late Devonian or Early Carboniferous age, was emplaced at < 2 kbar and displays the chemical characteristics of an A-type granite. It hosts small miarolitic pegmatites and dikes that belong to the NYF petrogenetic family, miarolitic class, miarolitic-REE subclass, with featur...

The El Portezuelo Granite (Catamarca Province, NW Argentina), probably of Late Devonian or Early Carboniferous age, was emplaced at < 2 kbar and displays the chemical characteristics of an A-type granite. It hosts small miarolitic pegmatites and dikes that belong to the NYF petrogenetic family, miarolitic class, miarolitic-REE subclass, with featur...

A new iron(III)/rhenium(VI) double perovskite oxide, Sr3Fe2ReO9, has been synthesized in polycrystalline form at 1200°C by solid-state reaction from citrate precursors. The Rietveld analysis of the synchrotron X-ray powder diffraction pattern shows that this compound, at 300K, has orthorhombic symmetry (S.G.: Immm), with a=5.56733(1)Å, b=5.56796(1)...

The dimorphs lipscombite and barbosalite, ideally Fe2+Fe3+2(PO4)2(OH)2, occur in El Criollo pegmatite (64°39'9"W, 31°21'28''S), Cerro Blanco, Córdoba, Argentina. In one of the intermediate zones of this pegmatite there is a nodule oftriplite discontinuously rimmed by the lipscombite-barbosalite-bearing assemblage. The primary paragenesis consists o...

The dimorphs lipscombite and barbosalite, ideally Fe2+Fe3+2(PO4)2 (OH)2, occur in El Criollo pegmatite (64°39′9″W, 31°21′28″S), Cerro Blanco, Córdoba, Argentina. In one of the intermediate zones of this pegmatite there is a nodule of triplite discontinuously rimmed by the lipscombite-barbosalite-bearing assemblage. The primary paragenesis consists...

The crystal structure of Nd[Fe(CN)6]·4H2O has been refined by Rietveld analysis using high resolution synchrotron powder X-ray diffraction data. It belonged to the orthorhombic crystal system, Cmcm space group, with cell parameters: a=7.473952(1)Å, b=12.919104(2)Å and c=13.800549(2)Å. The change in space group from P63/m which is observed in the pe...

In this paper we present the set up of the Rietveld analysis technique for the refinement of Powder X ray Diffraction (PXRD) patterns of Portland cement and clinker. We present results obtained for three samples of clinker and we compare these with the results obtained with Electronic Microscopy for two of the samples. We use PXRD taken with a labo...