The magnetic structure of the intermetallic compound ErGa has been determined using high-resolution neutron powder diffraction. This compound crystallizes in the orthorhombic (Cmcm, No. 63) CrB-type structure and orders ferromagnetically at 32 (2) K, with the Er moments initially aligned along the b axis. Upon cooling below 16 K, the Er magnetic moments cant away from the b axis towards the c axis. At 3 K, the Er moment is 8.7 (3) μB and the Er magnetic moments point in the direction 31 (3)° away from the crystallographic b axis, within the bc plane. 166Er Mössbauer spectroscopy work supports this structure and shows clear signals of the spin-reorientation in both the magnetic and electric quadrupole hyperfine interactions.

The structural and magnetic properties of Tb2Fe2Si2C have been investigated by bulk measurements (magnetisation and specific heat), X-ray diffraction, neutron powder diffraction and Fe-57 Mossbauer spectroscopy over the temperature range 3 K-300 K Tb2Fe2Si2C is antiferromagnetic with a Neel temperature T-N of 44(2) K. The magnetic structure can be described with a propagation vector k = [0 0 1/2] with the Tb magnetic moments ordering along the b-axis. We also observed strong magnetoelastic effects in particular along the a- and c-axes associated with the antiferromagnetic transition. The Fe-57 Mossbauer spectra show no evidence of magnetic splitting down to 10 K, indicating that the Fe atom is non-magnetic in Tb2Fe2Si2C. (C) 2015 Elsevier B.V. All rights reserved. 12 12

The Chainpur meteorite is one of 23 ordinary chondrites classified as LL3-type (low-Fe & low-metal). It was observed as a shower of stones falling on May 9, 1907 in Uttar Pradesh, India. We report here the characterization of the Fe-bearing phases in this chondrite using 57Fe Mössbauer spectroscopy carried out at 298 K, 120 K, 50 K and 13 K. The paramagnetic doublets of olivine and pyroxene dominate the room temperature spectrum, accounting for around 70 % of the spectral area. Moreover, a doublet present with a spectral area of 5 % and assigned to a superparamagnetic Fe 3+ phase is a consequence of terrestrial weathering. On the basis of the measured 57Fe electric quadrupole splitting of the olivine component at room temperature we estimate the mean Fe:Mg ratio in this meteoritic olivine to be around 35:65 % although there is clearly a wide range of composition. The effects of magnetic ordering of the major components olivine and pyroxene are observed at 13 K.

We have used neutron diffraction and 57Fe Mössbauer spectroscopy, complemented by magnetisation and specific heat measurements, to examine the magnetic ordering of Ho2Fe2Si2C. We have established that Ho2Fe2Si2C orders antiferromagnetically below TN = 16(1) K with a magnetic structure involving ordering of the Ho sublattice along the b-axis with a propagation vector k=[0 0 12]. 57Fe Mössbauer spectra collected below TN show no evidence of a magnetic splitting, demonstrating the absence of long range magnetic ordering of the Fe sublattice. A small line broadening is observed in the 57Fe spectra below TN, which is due to a transferred hyperfine field—estimated to be around 0.3 T at 10 K—from the Ho sublattice.

MnCoGe-based compounds are of interest with respect to the magnetocaloric effect due to a martensitic phase transition from the low-temperature orthorhombic phase to the high-temperature hexagonal phase. A key feature is that the transition temperature can be readily tuned to obtain a magneto-structural transition. Fe is an effective substitute for Mn or Co to stabilize the hexagonal phase at low temperature. Here we present initial 57Fe Mössbauer spectroscopy measurements on (Mn 0.96Fe 0.04)CoGe and Mn(Co 0.96Fe 0.04)Ge samples doped with 0.5 wt % 57Fe. The martensitic transition temperatures were determined to be 239 K and 304 K with transition full widths at half maximum of 44 K and 39 K respectively as determined from x-ray diffraction experiments over the temperature range 10–310 K. The magnetic properties were studied over the temperature range 5–300 K and a magneto-structural transition found in Mn(Co 0.96Fe 0.04)Ge. Analysis of the 20 K Mössbauer spectra reveals that the Fe atoms are distributed on both the Mn and Co sites and tend to prefer to occupy the Co site in both the (Mn 0.96Fe 0.04)CoGe and Mn(Co 0.96Fe 0.04)Ge samples. The hyperfine fields determined for Fe atoms on the Mn and Co sites at 20 K in the ferromagnetic orthorhombic phases are B hf−Mn= 16.4(4) T and B hf−Co= 21.1(4) T.

The magnetic and electronic properties of Eu2Ru2O7 are discussed in terms of the local ruthenium and europium coordination, electronic band structure calculations, and molecular orbital energy levels. A preliminary electronic structure was calculated within the local density approximation (LDA) and local spin density approximation taking in to account on-site Hubbard U (LSDA + U). The molecular orbital energy level diagrams have been used to interpret the Eu-Ru ligand spectrum and the ensuing magnetic properties. The orbital hybridizations and bonds are discussed.

The family of ternary intermetallic compounds R3T4X4 (R = rare-earth; T = d-element; X = Si, Ge, Sn) comprises over 100 members that have a generic orthorhombic structure (space group Immm, #71) at room temperature. We have observed a monoclinic <-> orthorhombic crystallographic transformation in Ho3Cu4Sn4, Er3Cu4Sn4 and Tm3Cu4Sn4 by high-resolution synchrotron X-ray and neutron powder diffraction. We show that the temperature at which this transformation occurs scales linearly with the ionic radius of the rare-earth. No such transformation was observed in Dy3Cu4Sn4, down to 1.7 K, consistent with this scaling. (C) 2014 Elsevier Ltd. All rights reserved.

Printed electronics is a rapidly growing area of research being explored for the manufacture of large‐area and cost‐effective electronic devices by the patterned application of functional inks. There are challenges associated with processing the inks compatible with inkjet printing technology and developing efficient methods to successfully obtain the desired features, particularly when it comes to metal and metal–organic complex inks. Here, a reliable method is developed to achieve a sophisticated microstructured pattern using the inkjet printing technique assisted by a surface charge reversal effect. In addition, a procedure is formulated to obtain good quality, stable metal–organic water‐based inks compatible with salts of a variety of transition metals and rare earths, without the need for additional volatile solvents. A feasible and water‐based ink formulation combined with a simple and noninvasive surface charge reversal treatment constitutes a major step toward the manufacture of high‐resolution, inorganic patterned thin films on hydrophobic substrates using inkjet printing. These outcomes lead to the path of effective fusion of inorganic and organic heterointerfaces by simples designing and printing.

We have used neutron powder diffraction to determine the magnetic structure of DyGa. This compound crystallises in the orthorhombic CrB-type structure with the Cmcm space group (#63) and the magnetic structure comprises ferromagnetic order of the Dy sublattice along the c-axis below TC=115K. Upon cooling below 25K, the Dy magnetic moments cant away from the c-axis towards the a-axis. At 3K, the Dy moment is 9.8(2) μB and the Dy magnetic moments point in the direction θ=22(2)°, ϕ=0° relative to the c-axis.

The MnCoGe family of compounds shows potential as a rare-earth free material for magnetocaloric applications around room temperature. We present initial findings on the effects of the substitution of Fe and Ni for Mn in a series of Mn{sub 1-x}T{sub x}CoGe compounds (T = Fe, Ni; x = 0.04 - 0.10). Investigations include x-ray diffraction, differential scanning calorimetry(200 - 670 K) and magnetisation (5 - 350 K) measurements in magnetic fields up to 8 T. The influence of the Fe and Ni substitutions on the transformation temperature between the hexagonal and orthorhombic structures, the resultant phase fractions and their magnetic phase transitions are reported.

We have determined the magnetic structure of the intermetallic compound TmGa by high-resolution neutron powder diffraction and 169Tm Mössbauer spectroscopy. This compound crystallizes in the orthorhombic (Cmcm) CrB-type structure and its magnetic structure is characterized by magnetic order of the Tm sublattice along the a-axis. The initial magnetic ordering occurs at 15(1) K and yields an incommensurate antiferromagnetic structure described by the propagation vector k1 = [0 0.275(2) 0]. At 12 K the dominant ferromagnetic ordering of the Tm sublattice along the a-axis develops in what appears to be a first-order transition. At 3 K the magnetic structure of TmGa is predominantly ferromagnetic but a weakened incommensurate component remains. The ferromagnetic Tm moment reaches 6.7(2) μB at 3 K and the amplitude of the remaining incommensurate component is 2.7(4) μB. The 169Tm hyperfine magnetic field at 5 K is 631(1) T.

Structural, 99Ru Mössbauer, dc and ac susceptibility magnetization, and magneto-transport properties of the polycrystalline Eu2Ru2O7 pyrochlore are reported in this paper. From the experimental data, we deduce that the ruthenium cations Ru4+ (S = 1) are surrounded by an unusual electronic environment, involving conduction electron polarization and extrinsic Eu3+ ions at low temperature. This situation leads to an anomalous spin-glass transition at 23 K.

We have determined the magnetic structure of the intermetallic compound HoGa by high-resolution neutron powder diffraction. This compound crystallizes in the orthorhombic (Cmcm) CrB-type structure and the magnetic structure comprises ferromagnetic order of the Ho sublattice along the c-axis. The Curie temperature is 66(3) K. Upon cooling below 20 K, the Ho magnetic moments cant away from the c-axis towards the ab-plane. At 3 K, the Ho moment is 8.8(2) mu(B) and the Ho magnetic moments point in the direction theta = 30(2)degrees and phi = 49(4)degrees with respect to the crystallographic c-axis. The observation of an ab-plane component at around 50 degrees from the a-axis is in contrast with the suggested magnetic structure of ac order (theta = 32 degrees and phi = 0 degrees) reported by Delyagin et al. [1] on the basis of a Sn-119 Mossbauer spectroscopy study of a Sn-doped HoGa sample. However, we find that these two sets of orientations are in fact indistinguishable by Mossbauer spectroscopy.

Two different series of ruthenium pyrochlores with the compositions Eu2−xCaxRu2O7 (0 ≤ x ≤ 0.6) and Eu2Ru2−xRexO7 (0 ≤ x ≤ 0.4) were prepared via solid state reaction, and their transport and magnetic properties were investigated. In both systems, the resistivity is shifted from 106 Ω cm to 10−3 Ω cm at low temperatures with increasing doping. The series correspond to two different approaches for inducing a metal–insulator transition in the Eu2Ru2O7 parent compound: (i) the substitution of Eu3+ by Ca2+, resulting in hole creation within the Ru t2g bands, and (ii) the partial substitution of Ru4+ (4d4) by Re4+ (5d3), leading to hole creation and an increase in the orbital overlap. Increasing the Ca or Re concentration suppresses the anomalies observed for Eu2Ru2O7 in dc magnetic susceptibility under zero-field-cooled and field-cooled conditions at 118 K and 23 K. In addition, a small negative magnetoresistance was obtained at low temperatures for doped samples with 2% Ca and Re.

We report a method of obtaining thin films of La0.85Ag0.15MnO3 using the chemical solution approach of polymer-assisted deposition. Epitaxial films with 25-30 nm thickness have been grown on single-crystal substrates of LaAlO3 (001) and SrTiO3 (001) exhibiting ferromagnetic Curie and metal-insulator transition temperatures shifted due to differences in the relaxation mechanisms of epitaxial misfit. High values of colossal magneto-resistance (−60% at 287 K and 5 T) were obtained in the case of LaAlO3 substrates which indicate that silver-doped manganite oxides have potential for room temperature applications.

The interest in functional ceramic coatings based on low cost and flexible manufacturing has been heightened by the effectiveness shown by chemical solution deposition of metal-organic salts, usually based on the use of spin coating, dip coating, or slot die coating techniques prior to thermal treatment to achieve decomposition of the starting salts. The possibility of implementing effective drop on demand systems in the manufacturing process allows a more efficient way to apply the precursor solution homogeneously onto the substrate, thus, enabling control of thickness of the ceramic coating, by controlling the drop size and the pitch of the printing pattern, among other manufacturing advantages such as control of solvent evaporation. In the present work, the authors report on their experiments concerning ink jet coating of functional complex ceramics for La0.7Sr0.3MnO3 and YBa2Cu3O7-x layers and patterns over single crystal and polycrystalline substrates using an electromagnetic system and a single nozzle piezoelectric dispenser. Characterization of rheological properties of the developed ink and of the resulting coating by optical microscopy, x-ray diffraction, scanning electron microscopy, and magnetic behavior are reported. (C) 2011 Society for Imaging Science and Technology [DOI: 10.2352/J.ImagingSci.Technol.2011.55.4.040304]

The magneto-structural transformation materials, which experience the crystallographic and magnetic phase transition simultaneously, have attracted considerable attention not only for their importance in fundamental physics but also for their promising applications as multifunctional materials.Magnetic refrigeration based on the magnetocaloric effect (MCE) is a possible alternative to the current vapor compression technology [1].Nowadays, most studies on magnetic refrigerants are focused on materials undergoing a first order phase transition because of their potential applications at room temperature.The CoMnGe 0.95 Ga 0.05 compound was prepared by arc melting by using high-purity elements.Synchrotron experiments were performed in the temperature range between 290 and 390 K on B2 in HASYLAB/DESY in Hamburg.A synchrotron X-ray wavelength of 0.688105 Å was used.Magnetic measurements were performed as functions of temperature and magnetic fields with Physical Properties Measurements System-PPMS between 5 and 350 K under magnetic field up to 7 Tesla.Synchrotron experiments shows that this compound exhibits the structural transition from high temperature phase (orthorhombic-space group: Pnma) to low temperature phase (cubic-space group: P6 3 /mmc) around the room temperature.According to Rietveld refinement, the unit cell volume of the high temperature phase is 77.3 Å 3 and the unit cell volume of low temperature phase is 160.9Å 3 at 300 K.According to temperature dependence of magnetization measurements, this compound has thermal hysteresis between FC and FH curves and this thermal hysteresis confirms the structural transition around T C .While on FC mode the Curie temperature is 308 K, the Curie temperature is 319 K on FH mode.According to M(H) curves, this compound exhibit magnetic field induced structural transition.This magneto-structural transition makes this material very important for magnetic cooling technology.The magnetocaloric effect of this compound is estimated by using Maxwell equation.The magnetic entropy change is 4.5 J/kg.K and 30.9 J/kg.K for the magnetic field change of 1 Tesla and 7 Tesla, respectively.

A new in-situ cell has been designed and constructed to simulate the temperature, pressure and chemical conditions present in deep saline aquifers.The cell has been built to study reactions at the CO 2brine-solid interfaces produced during injection of supercritical CO 2 (sc-CO 2 ) for storage and sequestration purposes.Much of the data relating to CO 2 storage relates to oil and gas wells.However, by far the largest potential reservoirs are deep saline aquifers where the chemistry has little in common with oil wells.Little experimental data exists on the behavior of various rocks and engineering materials under these conditions, particularly with injection of impure CO 2 streams, and some of the existing data give significant cause for concern.The cell has been designed for both reflection and transmission geometries so may be used both in laboratory and synchrotron environments.Although sc-CO 2 /water often reacts slowly under equilibrium, concerns have been raised about impurities such as SO 2 and H 2 S that will inevitably be present in industrial streams.These gases can react rapidly, so the slower laboratory and more rapid synchrotron measurements are highly complementary.Flow-through experiments may also be possible but haven't been specifically targeted.The cell has maximum working conditions of 300 bar pressure and 300 °C in pH3 brine conditions.These conditions are extremely demanding for any metals, sealing and window materials, and the restrictions imposed by the ASME Pressure Vessel and Boiler Code [1] and Process Piping Code [2] posed additional challenges.The materials certification requirements in the ASME code forced us into using structural grade beryllium windows as in our first generation cell [3].Beryllium is highly susceptible to chloride corrosion so a thin coating of tantalum is used to protect the windows under these conditions.Requirements of the pressure vessel certification process meant the cell was successfully tested hydrostatically to 450 bar pressure before delivery.Some of the theoretical and practical considerations for the design and construction of the cell will be described.Although the cell may be used with a laboratory diffractometer, the silver X-ray tube source and high-energy optimized PSD detector needed to gain sufficient penetration and signal are not standard components.Such a cell needs to be operated as part of an overall 'system' and is of limited use in isolation.

The ternary intermetallic system R3T4X4 (where R = rare earth; T = Mn, Cu, Ag, Au, Pd; X = Si, Ge, Sn) comprises an extensive series of isostructural compounds that form in the orthorhombic Gd3Cu4Ge4-type structure (space group Immm, #71). The exceptions to this generic structure are Tm3Cu4Sn4 and Lu3Cu4Sn4 which have a monoclinic structure (space group C12/m1, #12) at room temperature. Here, we report a structural phase transition in Tm3Cu4Sn4 from monoclinic C12/m1 to orthorhombic Immm upon heating above room temperature. We have carried out X-ray powder diffraction and differential scanning calorimetry on Tm3Cu4Sn4 and we observe the structural transition at 458(2) K.

We present results of High-resolution Transmission Electron Microscopy (HRTEM), and of the electrical and magnetic properties with various magnetic fields applied in bulk sample of EuSr2RuCu2O8 . Our data suggest that crystallographic shear planes observed by transmission electron microscopy could be originating the anomalies observed in the magnetic and electric measurements. These defects constitute a discontinuity in the Ru-O charge reservoir layers forming anti-phase boundaries, with big amounts of Eu between Ru layers locally deficient in O.