Inés Puente Orench

Institut Laue-Langevin · Diffraction

Low-temperature neutron diffraction experiments at P=8\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P= 8$$\end{document} GPa have been conducted to investigate the ma...

Heterogeneous bi-magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of Fe3 O4 /Mn3 O4 core/shell nanoparti...

Low-temperature neutron diffraction experiments at P = 8 GPa have been conducted to investigate the magnetic structures of metallic Holmium at high pressures by employing a long d-spacing highflux diffractometer and a Paris-Edinburgh press cell inside a cryostat. We find that at P = 8 GPa and T = 5 K, no nuclear symmetry change is observed, keeping...

In frustrated magnetic systems, the competition amongst interactions can introduce extremely high degeneracy and prevent the system from readily selecting a unique ground state. In such cases, the magnetic order is often exquisitely sensitive to the balance among the interactions, allowing tuning among novel magnetically ordered phases. In antlerit...

The newly synthesized Tm2Ir2O7 iridate is investigated using neutron scattering techniques. Powder neutron diffraction patterns confirm that Tm2Ir2O7 crystallizes in a cubic structure of pyrochlore type, consistent with the rest of the rare-earth A2Ir2O7 series, and the crystal structure is preserved down to 0.2 K. The thermal expansion of the crys...

Magnetic frustration, the competition among exchange interactions, often leads to novel magnetic ground states with unique physical properties which can hinge on details of interactions that are otherwise difficult to observe. Such states are particularly interesting when it is possible to tune the balance among the interactions to access multiple...

The incorporation of multiple metal atoms in multivariate metal-organic frameworks is typically carried out through a one-pot synthesis procedure that involves the simultaneous reaction of the selected elements with the organic linkers. In order to attain control over the distribution of the elements and to be able to produce materials with control...

In frustrated magnetic systems, the competition amongst interactions can introduce extremely high degeneracy and prevent the system from readily selecting a unique ground state. In such cases, the magnetic order is often exquisitely sensitive to the balance among the interactions, allowing tuning among novel magnetically ordered phases. In antlerit...

The magnetic lanthanide (Ln3+) ions in the fergusonite and scheelite crystal structures form a distorted or stretched diamond lattice which is predicted to host exotic magnetic ground states. In this study, polycrystalline samples of the fergusonite orthotantalates M−LnTaO4 (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er) were synthesized and then characteriz...

Magnetic frustration, the competition among exchange interactions, often leads to novel magnetic ground states with unique physical properties which can hinge on details of interactions that are otherwise difficult to observe. Such states are particularly interesting when it is possible to tune the balance among the interactions to access multiple...

The magnetic Ln$^{3+}$ ions in the fergusonite and scheelite crystal structures form a truncated hyperhoneycomb net that can be labelled as $^{\mathcal{H}}\langle-1\rangle$ by analogy with the harmonic honeycomb series $^{\mathcal{H}}\langle N\rangle$ [Modic et al., Nat. Commun. 5, 4203 (2014)]. This $^{\mathcal{H}}\langle-1\rangle$ magnetic lattic...

The antiferromagnetic (AFM) transition of the normal ZnFe2O4 has been intensively investigated with results showing a lack of long-range order, spin frustrations, and a "hidden" en-tropy in the calorimetric properties for inversion degrees δ ≈ 0 or δ = 0. As δ drastically impacts the magnetic properties, it is logical to question how a δ value slig...

Samples with inversion parameter values (δ) ranging from 0.27 to 0.14 while maintaining the crystallite size value have been successfully fabricated from commercially available powders by mechanical grinding and thermal annealing treatments at temperatures ranging between 400 and 600 °C. Detailed characterization studies of these samples using X-ra...

Bulk Cr 2 O 3 is an antiferromagnetic oxide that exhibits the magneto-electric effect at room temperature, with neither spontaneous magnetization nor net electric polarization. These physical properties stem from a subtle competition...

Yb- and Ce-based delafossites were recently identified as effective spin-1/2 antiferromagnets on the triangular lattice. Several Yb-based systems, such as NaYbO2, NaYbS2, and NaYbSe2, exhibit no long-range order down to the lowest measured temperatures and therefore serve as putative candidates for the realization of a quantum spin liquid. However,...

Yb- and Ce-based delafossites were recently identified as effective spin-1/2 antiferromagnets on the triangular lattice. Several Yb-based systems, such as NaYbO2, NaYbS2, and NaYbSe2, exhibit no long-range order down to the lowest measured temperatures and therefore serve as putative candidates for the realization of a quantum spin liquid. However,...

ThMn12 nitrides are good candidates for high performance permanent magnets. However, one of the remaining challenges is to transfer the good properties of the powder into a useful bulk magnet. Thus, understanding the denitrogenation process of this phase is of key importance. In this study, we investigate the magnetic and structural stability of th...

Abstract: The antiferromagnetic (AFM) transition of the normal ZnFe2O4 has been intensively Investigated with results showing a lack of long-range order, spin frustrations, and a “hidden” entropy in the calorimetric properties for inversion degrees δ ≈ 0 or δ = 0. As δ drastically impacts the magnetic properties, it is logical to question how a δ v...

The correlation between ex situ electronic conductivity, oxygen vacancy content, flat-band potential (Efb), and the oxygen evolution reaction (OER) activity for a wide range of perovskite compositions are investigated experimentally and theoretically. It is found that all of these parameters can affect the OER activity; however, none of them alone...

Recently, potential technological interest has been revealed for the production of magnetocaloric alloys using Rare-Earth intermetallics. In this work, three series of TbxR1−xCu2 (R ≡ Gd, La, Y) alloys have been produced in bulk and nanoparticle sizes via arc melting and high energy ball milling. Rietveld refinements of the X-ray and Neutron diffra...

The precise control on the combination of multiple metal atoms in the structure of metal-organic frameworks (MOFs) endowed by reticular chemistry, allows the obtaining of materials with compositions that are programmed for achieving enhanced reactivity. The present work illustrates how through the transformation of MOFs with desired arrangements of...

We report on structural and magnetic properties of a SmCuAl3 single crystal. The sample quality, phase and structure purity were investigated by means of x-ray and neutron diffraction, BSE electron microscopy and EDX analysis. The crystal structure was identified to be of a tetragonal BaNiSn3-type (space group I4mm, 107). Magnetization measurements...

Interest in strongly correlated electron system $\text{YbAl}_3$ has been recently renewed by the observation of a breakdown of coherence effects and Fermi liquid behavior when the alloy reduces its particle size down to around 11 nm. Powder diffraction measurements using neutron and synchrotron radiation allow us to estimate the thermal expansion...

In the present contribution, we report how through the use of metal-organic frameworks (MOFs) composed of addressable combinations of up to four different metal elements it is possible to program the composition of multi-metal oxides, which are not attainable by other synthetic methodologies. Thus, due to the ability to distribute multiple metal ca...

Magnetic properties of PrCuAl3 and NdCuAl3 single crystals, adopting the tetragonal BaNiSn3-structure-type, are reported. Our magnetization and specific heat measurements revealed no magnetic ordering in PrCuAl3, while NdCuAl3 orders antiferromagnetically below TN = 2.45 K. The paramagnetic regime was investigated for both analogues revealing (i) t...

We report on the strong changes induced, by confinement, in the microstructure of the semiconductor poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) and its photovoltaic blend with [6,6]-Phenyl-C71-butyric acid methyl ester (PC71BM). These organic compounds can be used as model systems to illustrate how sensitive this class of...

In the present contribution, we report how through the use of metal-organic frameworks (MOFs) composed of addressable combinations of up to four different metal elements it is possible to program the composition of multi-metal oxides, which are not attainable by other synthetic methodologies. Thus, due to the ability to distribute multiple metal ca...

We present a systematic powder neutron diffraction study on Sr-based M-type hexaferrites SrScxFe12−xO19 using high-resolution and high-flux instruments. We have derived the magnetic configurations for the compounds with x=1.4, 1.6, and 1.8 at room temperature and at 2 K revealing a ferrimagnetic structure and a complex conical magnetic structure, r...

The correlation between ex situ electronic conductivity, oxygen vacancy content, Flatband Potential (Efb), and the oxygen evolution reaction (OER) activity for a wide range of perovskite compositions (La1-xSrxCoO3- series (with x = 0, 0.2, 0.4, 0.6, 0.8), LaMO3- series (M = Cr, Mn, Fe, Co, Ni), Ba0.5Sr0.5Co0.8Fe0.2O3- (BSCF) and PrBaCo2O6- (PBC...

The preparation of materials with structures composed of multiple metal cations that occupy specific sites is challenging owing to the difficulty of simultaneously addressing the incorporation of different elements at desired precise positions. We report how it is possible to use a metal-organic framework (MOF) built with a rod-shaped inorganic sec...

The perovskite series Sr2CoNb1-xTixO6-δ (0≤x≤1) is investigated in the full compositional range to assess its potential as cathode material for solid state fuel cell (SOFC). The variation of transport properties and thus, the area specific resistances (ASR) are explained by a detailed investigation of the defect chemistry. Increasing titanium conte...

While the majority of research activities on LiCoPO4 is focussed on the thermodynamically stable olivine-type Pnma polymorph, the metastable Pna21 and Cmcm modifications have recently attracted considerable attention due to their interesting material properties. In this study, we present the first Li-deficient structural derivative of the Cmcm modi...

Topochemical nitridation in ammonia at moderate temperatures of cation ordered Sr2FeWO6 produces new antiferromagnetic double perovskite oxynitrides Sr2FeWO6-xNx with 0 < x ? 1. Nitrogen introduction induces the oxidation of Fe(2+) to Fe(3+) and decreases TN from 38 K (x = 0) to 13 K for Sr2FeWO5N which represents the first example of a double pero...

CePd2Al2−xGax compounds crystallizing in the tetragonal CaBe2Ge2-type structure (space group P4/nmm) and undergoing a structural phase transition to an orthorhombic structure (Cmme) at low temperatures were studied by means of neutron scattering. The amplitude-modulated magnetic structure of CePd2Al2 is described by an incommensurate propagation ve...

Short-range structural and magnetic order in rapidly solidified nanostructured Ag100 − xMnx alloys featuring nominal large Mn content (x = 25, 32, 40 at.%), well above the maximum equilibrium concentration (x ~ 14 at.%), are quantified using X-ray, neutron and magnetic probes. These inhomogenous alloys contain coexisting Mn-rich and Mn-deficient na...

Lu(Fe0.75Al0.25)2 and Lu(Fe0.50Al0.50)2 alloys have been produced by arc-melting. DC and AC magnetization, Mössbauer spectroscopy, specific heat and neutron diffraction experiments have been performed to determine their magnetic ground state. DC magnetization curves measured at low fields (H < 1 kOe) evidence two peaks, at TSRO and Tf, and magnetic...

The microstructure of high temperature shape memory alloys of the Ru-Ta and Ru-Nb family are investigated in detail. After cooling from the high temperature cubic b phase the off-stoichiometric alloys show a compound twinning in the tetragonal beta' phase which prevails at room temperature and can be observed as two levels of laminates A and C [1]....

Among all antiferromagnetic transition metal monoxides, NiO presents the highest Néel temperature (TN ∼ 525 K). In this work, the size-dependent reduction of TN in NiO nanoparticles with average diameters (D) ranging from 4 to 9 nm is investigated by neutron diffraction. The scaling law followed by TN(D) is in agreement with the Binder theory of cr...

In the last decade, the renewed interest in antiferromagnetic (AF) magnetoelectric (ME) materials has been driven by the challenging multifunctionality of spintronic devices. One of the most ambitious goals is to build exchange-biased ferromagnetic/AF junctions with electric field-controlled properties. In this context, the understanding of the mod...

Recently, the development of miniaturized gas-sensing devices, particularly for toxic gas detection and pollution monitoring, has been the subject of intense research. A wide range of materials are available for acetone sensors, where the competition between the intermolecular forces and the molecule-substrate interactions plays a crucial role. Des...

The unexpected appearance of magnetic hysteresis and exchange bias effects in nominally antiferromagnetic NiO nanoparticles is usually explained in terms of a core/shell morphology, where a spin glass-like shell is exchange coupled to an antiferromagnetic core. However, recent studies have challenged the validity of this assumption for small enough...

NiO nanoparticles (NPs) with a nominal size range of 2–10 nm, synthesized via hightemperature pyrolysis of a nickel nitrate, have been extensively investigated using neutron diffraction and magnetic (ac and dc) measurements. The magnetic behavior of the NPs changes noticeably when their diameter decreases below 4 nm. For NPs larger than or equal to...

Among all bi-magnetic core(transition metal)@shell(transition metal oxide) nanoparticles (NPs), Ni@NiO ones show an onset temperature for the exchange bias (EB) effect far below the Néel temperature of bulk antiferromagnetic NiO. In this framework, the role played by the magnetism of NiO at the nanoscale is investigated by comparing the microstruct...

D1B is a medium resolution high flux powder diffractometer located at the Institut Laue Langevin, ILL. D1B a suitable instrument for studying a large variety of polycrystalline materials. D1B runs since 1998 as a CRG (collaborating research group) instrument, being exploited by the CNRS (Centre National de la Recherche Scientifique, France) and CSI...

Studies of the liquid state present an obvious fundamental interest and are also important for technological applications since the molten state is an essential stage in various industrial processes (e.g. glass making, single crystal growing, iron and steel making). Most of the physical properties of a high-temperature liquid are related to its ato...

We show that the combination of dielectric relaxation with neutron spin echo and incoherent neutron backscattering measurements performed in deuterated and protonated poly(ethylene terephthalate) suggests that the intrinsic dynamics of semicrystalline polymers occurs in an homogeneous scenario, similar to that valid to describe the dynamics of tota...

Several pseudo-binary RxR'2-xFe17 alloys (with R = Y, Ce, Pr, Gd and Dy) were synthesized with rhombohedral Th2Zn17-type crystal structure determined from x-ray and neutron powder diffraction. The choice of compositions was done with the aim of tuning the Curie temperature (TC) in the 270 ± 20 K temperature range, in order to obtain the maximum mag...

Ru-based high temperature shape memory alloys show different structures at different temperatures and composition. Equiatomic Ru–Ta and Ru–Nb show two subsequent phase transformations, but their individual influence is still unclear because of the difficulty of comparing the high temperature cubic phase, the intermediate tetragonal phase and the lo...

In the paper by Solano et al. [J. Appl. Cryst. (2014), 47, 414–420], Ines Puente Orench is missing from the list of authors. The complete list of authors should be Eduardo Solano, Carlos Frontera, Ines Puente Orench, Teresa Puig, Xavier Obradors, Susagna Ricart and Josep Ros.

Transformation of deuterated ethanol from the plastic crystal phase into the monoclinic one is investigated by means of a singular setup combining simultaneously dielectric spectroscopy with neutron diffraction. We postulate that a dynamic transition from plastic crystal to supercooled liquid-like configuration through a deep reorganization of the...

Procedures based on equilibrium conditions (stress and bending moment) have been used to obtain an unstressed lattice spacing, d0, as a crucial requirement for calculating the residual stress (RS) profile across a joint conducted on a 10 mm thick plate of age-hardenable AA2024 alloy by friction stir welding (FSW). Two procedures have been used that...

We have synthesized the Dy2Fe17 alloy with an unconventional crystal structure (R (3) over barm space group). Neutron powder thermo-diffraction and X-ray powder diffraction under high pressure (up to 15 GPa) show that the rhombohedral crystal structure is stable. Likewise, the alloy with the usual hexagonal crystal structure (P6(3)/mmc), the rhombo...

The exchange mechanism and magnetic structure of the organic-inorganic layered molecule-based magnet [Co2(bta)]n (1) (H4bta =1,2,4,5-benzenetetracarboxylic acid) have been investigated through variable-temperature magnetic susceptibility measurements and supported with a series of neutron diffraction experiments. Cryomagnetic studies have shown an...

Here we show that spontaneous oxidation of MnO nanoparticles into MnO/Mn3O4 core/shell nanoparticles has the effect of a local pressure, decreasing the MnO cell parameter and increasing strain, resulting in the increase of the MnO antiferromagnetic/paramagnetic transition temperature TN. These effects are more severe in smaller nanoparticles.

Export Date: 28 May 2012, Source: Scopus, Article in Press

One of the simplest ways to confine polymeric materials is by self-assembling during the crystallization process. The remaining amorphous phase is then constrained by the lamellar crystals. In this manuscript, we aim to shed additional light in the understanding of the amorphous chains dynamics of semicrystalline polymers above the Tg by using inco...

Combining different experimental techniques, investigations in hexagonal P63/mmc Er2Fe17 show remarkable magnetovolume anomalies below the Curie temperature, TC. The spontaneous magnetostriction reaches 1.6×10−2 at 5 K and falls to zero well above TC, owing to short-range magnetic correlations. Moreover, Er2Fe17 exhibits direct and inverse magnetoc...

The breathing of the flexible metal organic framework MIL-53(Cr) has been widely explored by both experimental and modeling approaches upon the inclusion of different guest molecules within its porosity. This spectacular phenomenon has been only partially tackled by force field based simulations mainly due to the complexity of deriving a set of acc...

We report on the magnetic structures in the TbNiAl1−xInx compounds as determined by powder neutron diffraction. These compounds belong to a large family of ternary rare-earth intermetallics crystallizing in the ZrNiAl-type hexagonal structure. All studied compounds order magnetically with magnetic structures characterized by k1=(0,0,0) and k2=(1/2,...

We have synthesized the intermetallic YPrFe17 compound by arc-melting. X-ray and neutron powder diffraction show that the crystal structure is rhombohedral with space group R-3m (Th2Zn17 -type). The investigated compound exhibits a broad magnetic entropy change ΔS M (T) associated with the ferro-to-paramagnetic phase transition (T C ≈ 290 K). The i...

We report a study on neutron diffraction and magnetic properties ol cobalt oxide CoO antiferromagnetic nanoparticles with different sizes. The nanoparticles are composed by a structurally and magnetically ordered core and a structurally ordered and magnetically disordered shell with a thickness of about 2 nm. The ordered core has cell parameters, m...

Neutron powder diffraction shows that the intermetallic Er 2 Fe 17 compound with hexagonal crystal structure has a ferrimagnetic ground state (T C = 303 K). At T = 5 K the magnetic moments of Fe sublattice (µ ~ 2 µ B) are therefore antiparalell to those of the Er one (µ ~ 9 µ B), all of them lying on the basal plane. This compound exhibits strong m...

Neutron diffraction techniques have been used to determine the low temperature crystal structure and to shed light on the magnetic behavior of the [Mn(3)(suc)(2)(ina)(2)](n) (suc = succinate and ina = isonicotinate) complex. The ferromagnetic signal observed below T(c) ≈ 5 K in this compound is due to a noncompensation of homometallic spins in the...

Transformation of deuterated ethanol from supercooled liquid into a plastic crystal or rotator phase is investigated by means of a particular experimental setup combining simultaneously dielectric spectroscopy with neutron diffraction techniques. We demonstrate that, previous to the growth of the bcc lattice of the plastic crystal phase, the format...

We report a study on the remanent magnetization Mr induced by field cooling across the ordering temperature TN in antiferromagnetic CoO nanoparticles with different sizes. The nanoparticles are composed by a structurally and magnetically ordered core and a structurally ordered and magnetically disordered shell with a thickness of about 2 nm. The or...