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Oleic acid/oleylamine capped Fe1-xPdx(x=0.16, 0.20, 0.25) nanoparticles have been synthesized using a diol as reducing agent in order to get nanoparticles of different average sizes and coatings. Composition and morphology were analyzed by infrared spectroscopy (IR), X-Ray Diffraction (RXD), thermogravimetry (TG) and Transmission Electron Microscopy (TEM). Well dispersed nanoparticles with uniform sizes between 3 and 8 nm and average diameters less than 6 nm were obtained. Magnetic properties were investigated by Electron Magnetic Resonance (EMR) and magnetization measurements. Most of the nanoparticles were superparamagnetic at physiological temperature with low magnetic saturation values (near 5 emu.g-1alloy/0.4 N per Fe atom). SAR measurements were also performed with the aim of carrying out hyperthermia measurements but the nanoparticles did not work as magnetic heaters.

The magnetic and optical properties of regioregular poly(3-hexylthiophene)-capped Au nanoparticles (NPs) have been investigated in order to clarify the effectiveness of polythiophene capping on the induction of ferromagnetism in Au. The room-temperature magnetization curve of the polythiophene-capped Au NPs exhibits a clear hysteresis behavior with a spontaneous magnetization of 8.5 x 10-3 emu/g. The average magnetic moment of the surface Au atoms is estimated to be 2.6 x 10-3 B. The ultraviolet-visible spectrum shows a clear sign of the surface plasmon absorbance of metallic Au which reflects the week character of the chemical bond between the Au and S atoms on capping surface. Our results show clearly that Au NPs capped with polythiophene can be ferromagnetic.

Copper is known as a pearlite promoter in cast iron and has been used as such for a long time, most often together with low amounts of manganese. Literature data, however, has shown that these two elements act differently on the ferritic and pearlitic transformations. In order to provide more insight in the role of this element on the solid-state transformation of spheroidal graphite (SG) cast iron, this paper investigates the effect of adding copper in small step increments, from 0.11 to 1 wt. % Cu, to SG irons containing about 0.15 wt. % Mn. The characteristic temperatures for the stable and metastable eutectoid transformations as recorded during cooling after solidification in standard cups and after austenitizing are presented together with microstructure information. It is found that a copper content of about 0.6 wt. % is the upper limit over which only small amounts of ferrite could be obtained except at very low cooling rates. This is tentatively related to the lowering of the temperature for ferrite and the associated decreased kinetics for austenite decomposition in the stable system.

The sarkinite, Mn2(OH)AsO4, mineral has been synthesized in laboratory as pure phase under mild hydrothermal conditions. The decomposition process of the hydroxiarsenate compound is strongly dependent on the atmospheric conditions. The results of the thermal treatment in air or argon are quite different. In this way, a new black phase appears in air atmosphere in the 400‐630 °C temperature range whereas under inert atmosphere the structure of Mn2(OH)AsO4at room temperature is maintained up to 560 °C. The weight loss is attributed to the partial decomposition of Mn2(OH)AsO4above 400 °C with removal of OH groups and the oxidation of MnIIto MnIIIthat occur simultaneously. Above 650 °C, the structures of the intermediate compounds are broken and the evolution of the inorganic residues gives rise to the formation of arsenates and oxides of MnIIand MnIIIin inert and air atmospheres.

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Polycrystalline samples of the mixed-valence perovskite-type manganites Sm0.35Nd0.35M0.3Mn1—xFexO3 (M = Pb, Cd; x = 0, 0.1) have been synthesised and their magnetic and transport properties studied. Magnetic measurements show that TC values decrease considerably with the presence of cadmium or iron. Colossal magnetoresistance has been shifted to lower temperatures. Values of magnetoresistance near to 40% have been obtained. The presence of defined maxima in the real part of ac susceptibility at the same temperature of the cusp in the zero field cooling curves corroborates cluster-glass behaviour.

The Nd0.7A0.3Mn1-xBxO3 (A = Pb, Cd; B = Fe, Co, Ni; x = 0, 0.1) compounds have been synthesized using the sol−gel method and characterized by redox titration and X-ray diffraction. The replacement of manganese ions by Fe, Co or Ni implies a decrease in the ferromagnetic (or metal−insulator) transition temperature. The ZFC magnetization drops to zero at low temperatures, showing a general weakening of the ferromagnetic DE interactions and an increasing contribution of the AFM ones arising by superexchange. Similar effects have been observed in the cadmium phases but substitutions of Fe, Co and Ni cations do not modify the magnetic behavior of these phases. The difference observed between the para-ferromagnetic transition temperature, Tc, and the metal−insulator one could be explained because of the appearance of magnetically inhomogeneous regions. Values of magnetoresistance around 70% for the lead compounds have been obtained. From ESR measurements at room temperature for all of the samples, different line widths related to the kind of metals present in the cell and the corresponding Tc have been obtained. The line width values are higher for the cadmium phases than those for the lead ones, and within each family, it increases as follows:  Ni < Fe < Co.

Compounds with general formula [KxMyNi(NO2)6(H2O)n] (M=Ca, Sr, Ba, La;x=0–2; y=1, 2; n=0, 4) have been prepared and characterized by XRD, IR and EPR techniques. The structure of [Ba2Ni(NO2)6(H2O)2 ]2H2O has been determined by single crystal X-ray diffraction: space group P63 , a=7.525(1) Å and c=14.516(1) Å. The geometry of the compound consists of an intricate network of ligand-bridged coordination polyhedra, where the arrangement of the nickel(ii) ion exhibits a slightly distorted octahedral topology. The Ca, Sr and La phases have been indexed with a cubic cell, space group Pm3 m and cell parameters 10.354(5) Å, 10.517(5) Å and 10.571(8) Å, respectively. Thermal decomposition of the different compounds using TG involves two consecutive steps: ligand pyrolysis and evolution of the inorganic residue. For the barium compound a third step appears which corresponds to the dehydration process. Further thermal treatments in tubular furnaces yield the formation of different mixed oxides of NiIII and NiIV at lower pressures of oxygen than those obtained from the ceramic method. Advantages of using the metallo–organic method can also be deduced from the SEM study.

The new layered HNiPO4·H2O compound has been prepared and characterized, and its crystal structure resolved. It crystallizes in the monoclinic P21 space group with cell parameters a = 8.069(3), b = 4.726(1), c = 5.597(1) Å, β = 109.62(2)°, V = 201.04 ų, Z = 2. The structure consists of (100) sheets of NiO6 corner-sharing octahedra cross-linked by (HPO4) groups. These sheets are linked by a zig-zag system of hydrogen bonds along the [010] direction, involving the (OH) group of the (HPO4) tetrahedra arranged toward the interlayer space. Five different alkyl amines, CnH2n+1NH2 (n = 3−7), have been intercalated in this compound to form the (CnH2n+1NH2)xHNiPO4·H2O phases. The intercalated derivatives present the inserted alkylamines arranged in bilayers and tilted at an angle of approximately 53.2° with respect to the inorganic sheets. The extent of intercalation is approximately constant (0.75) with the only exception being butylamine. No changes in particle size and morphology have been observed during the intercalation reactions. Thermal studies suggest that the alkyl amine desorption in these compounds takes place in only one step. Magnetic measurements of (C7H15NH2)0.76HNiPO4·H2O show the existence of essential 2D antiferromagnetic intralayer interactions. In the case of HNiPO4·H2O, an increase 3D interlayer ordering appears when temperature decreases due to the presence of hydrogen bonds between layers in the structure of this compound.

Both spectrosphotometric and kinetic evidence is offered concerning the main features of the production of colloidal Mn(IV) originating from the permanganate oxidation of glycine, alanine and phenylalanine. The analysis of the time of colloid formation supports the notion that glycine and phenylalanine participate in the colloid structure.

Three new compounds of generalised formula [Cu(LIII)XY]?nH2O [LIII=pymep, terpy; X=I, N3; Y=I, NO3, PF6; n=0,1], pymep (C14H15N3)=N-(6methyl?2-pyridyl?methylene) -2-(2-pyridyl)-ethylamine and terpy (C15H11N3)=2,2?;6?,2?-terpyridine have been prepared by reaction in solution. Crystal data were determined by single-crystal methods. Powder diffraction data and densities determined by a flotation method are also presented.

In order to decrease the global dependence on fossil fuels, high energy density, rechargeable batteries with high charge capacity are required for mobile applications and efficient utilization of intermittent sources of renewable energy. Metal-air batteries are promising due to their high theoretical energy density. In particular, the iron-air battery, with a maximum specific energy output of 764 W h kg−1Fe, represents a low cost possibility. This paper considers an iron-air battery with nanocomposite electrodes, which achieves an energy density of 453 W h kg−1Feand a maximum charge capacity of 814 mA h g−1Fewhen cycled at a current density of 10 mA cm−2, with a cell voltage of 0.76 V. The cell was manufactured by 3D printing, allowing rapid modifications and improvements to be implemented before an optimized prototype can be manufactured using traditional computer numerical control machining.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.