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Mo-Re-C compounds containing Mo 7 Re 13 C with the β-Mn structure were synthesized with high-melting-temperature metals Mo, Re, and C powders using a conventional solid state method with a planetary ball milling machine instead of the arc melting method. Use of the ball milling machine was necessary to obtain Mo 7 Re 13 C with the β-Mn structure using the solid state method. Almost single-phase Mo 7 Re 13 C with a trace of impurity were obtained using the synthesis method. By XRF and lattice parameter measurements on the samples, Fe element existed in the compound synthesized using the planetary ball milling machine with a pot and balls made of steel, though Fe element was not detected in the compound synthesized using a pot and balls made of tungsten carbide. The former compound containg the Fe atom did not show superconductivity but the latter compound without the Fe atom showed superconductivity at 6.1 K. [ABSTRACT FROM AUTHOR]

We fabricated dense aluminum nitride ceramics by spark plasma sintering (SPS) with Y 2 O 3 –CaO–B sintering additives and evaluated their microstructures and thermal conductivities. Samples were perfectly densified after 5 min of SPS at 1650 or 1600 °C, or 10 min at 1550 °C and had fine microstructures. Thermal conductivities of the samples were 80–90 W m −1 K −1 and tended to increase with increasing sintering temperature. [ABSTRACT FROM AUTHOR]

We compared reactivity between CO2 and Li2CuO2 with that between CO2 and Li4SiO4 by using XRD, SEM observation, and thermogravimetry in order to study fundamentally a potential of Li2CuO2 oxide for application to solid CO2 absorbents. The CO2 absorption ability of Li2CuO2 was examined by measuring rate constants for the gas–solid reaction between perfectly single-phase Li2CuO2 and CO2 at various temperatures in 100vol% CO2 atmosphere using the rate theory with thermogravimetry using rapid heating. The measured rate constants were compared with those reported previously for Li4SiO4 at various temperatures. Almost no difference was found between these rate constants of Li2CuO2 and Li4SiO4 at temperatures less than 660°C, but at temperatures higher than 670°C, the rate constants of Li2CuO2 were greater than those of Li4SiO4. These results demonstrate that Li2CuO2 can outstrip the ability of Li4SiO4 to absorb CO2. Moreover, different from Li4SiO4, the CO2 absorption ability of Li2CuO2 decays only slightly, even if the atmospheric CO2 concentration decreases. [ABSTRACT FROM AUTHOR]

First time, the title compound is prepared by solid state reaction of stoichiometric amounts of PbO, PbF2 (slight excess), and TiO2 (Pyrex tubes, 823 K, 12 h). [ABSTRACT FROM AUTHOR]

Magnetic coordination polymers can exhibit controllable magnetism by introducing responsiveness to external stimuli. This report describes the precise control of magnetism of a cyanide-bridged bimetallic coordination polymer (Prussian blue analogue: PBA) through use of an electrochemical quantitative Li ion titration technique, Le., the galvanostatic intermittent titration technique (GITT). Ko.2Ni[Fe(CN)6]o.74.7H2O(NiFe-PBA) shows Li ion insertion/extraction reversibly accompanied with reversible Fe3+/Fe2+ reduction/oxidation. When Li ion is inserted quantitatively into NiFe-PBA, the ferromagnetic transition temperature Tc gradually decreases due to reduction of paramagnetic Fe3+ to diamagnetic Fe2+, and the ferromagnetic transition is completely suppressed for Li0.5(NiFe-PBA). On the other hand, Tc increases continuously as Li ion is extracted due to oxidation of diamagnetic Fe2+ to paramagnetic Fe3+, and the ferromagnetic transition is nearly recovered for Li0(NiFe-PBA). Furthermore, the plots of Tc as a function of the amount of inserted/extracted Li ion x are well consistent with the theoretical values calculated by the molecular-field approximation. [ABSTRACT FROM AUTHOR]

Abstract: Interfacial charge transfer is a fundamental issue in both science and technology of the batteries. In this report, interfacial alkali-ion transfer between the cyanide-bridged coordination polymer (Prussian blue analogue, PBA) electrode and organic electrolytes was investigated. Electrochemical impedance spectroscopy (EIS) suggested that alkali-ion transfer at the K0.1Mn[Fe(CN)6]0.7·3.6H2O (MnFe-PBA) electrode–electrolyte interface involves two processes. One process could be interpreted as the ion transfer between the Outer Helmholtz Plane (OHP) and Inner Helmholtz Plane (IHP) including the solvation/desolvation process, the other could be interpreted as that between the IHP and electrode, including ad-ion diffusion on the electrode surface. Temperature dependence of the charge transfer resistances gave the activation energy for each process. The activation energy for Li-ion transfer between the OHP and IHP in propylene carbonate (PC) electrolyte is almost constant at the composition range of 0.1< x <0.6 in Li x MnFe-PBA, which is comparable to that in ethylene carbonate (EC)-diethyl carbonate (DEC) electrolyte. In contrast, the activation energy for Li-ion transfer between the IHP and electrode depends largely on the Li-ion concentration in the PBA electrode. However, the averaged value for Li-ion transfer is higher than that for Na-ion transfer. This result indicated that Li-ion on the PBA surface diffuses with higher potential barrier than Na-ion. Furthermore, the effect of the interfacial charge transfer resistance was evaluated by the high charge/discharge rate experiments. [Copyright &y& Elsevier]

Polycrystatine samples of Ln18Li8Rh5-xFexO39 (Ln = La, Nd; 0.5 ⩽ x ⩽5) have been synthesized by a solid-state method and studied by a combination of dc and ac magnetometry, neutron diffraction, and Mössbauer spectroscopy. All compositions adopt a cubic structure (space group Prn3n, ao ∼ 12 A) based on intersecting (111> chains made up of alternating octahedral and trigonal-prismatic coordination sites. These chains occupy channels within a Ln-O framework. At low values of x, iron preferentially occupies the smaller (2a) of the two distinct octahedral sites as tow- spin Fe(IV). The Rh(lll) on the larger (8e) octahedral site is replaced by high-spin Fe(lll). Nd-containing compositions having x> 1 show spin-glass-like behavior below ∼5 K. La-containing compositions having x> 1 show evidence of a magnetic transition at ∼8 K, but the nature of the transition is unclear. This contrasting behavior demonstrates that, although the structural chemistry of the two systems is essentially the same, the magnetic character of the Ln cations plays an important role in determining the properties of these compounds. [ABSTRACT FROM AUTHOR]

Polycrystalline samples of Nd18Li8Fe5O39 and Nd18Li8Co4O39 have been synthesized using a solid-state method and studied by a combination of neutron diffraction, direct and alternating current magnetometry, and, in the case of Nd18Li8Fe5O39, Mössbauer spectroscopy. Both compounds adopt a cubic structure (space group Pm3n, a0 ∼11.9 Å) based on intersecting <111> chains made up of alternating octahedral and trigonal-prismatic coordination sites. The Fe4+ cations in Nd18Li8Fe5O39 are found on only the smaller of the two distinct octahedral sites in the structure; Fe3+ and Li+ are disordered over the larger octahedral site and the trigonal-prismatic site. The Nd3+ cations occupy sites between the chains. The smaller octahedral site is fully occupied by cobalt in Nd18Li8Co4O39, with 25% of the larger octahedral sites being vacant; Li+ is only found on the prismatic sites. Nd18Li8Fe5O39 shows spin-glass-like behavior with a spin-freezing temperature of 5.75 K, whereas Nd18Li8Co4O39 appears to order antiferromagnetically at 2.3 K. In both cases, the magnetic coupling involves the Nd3+ sublattice. [ABSTRACT FROM AUTHOR]

The structure proposed for Li11Nd18Fe4O39-δ (Chen et al. Inorg. Chem. 2012, SI, 8073) on the basis of diffraction and Mossbauer spectral data is compared to that determined previously for Nd18Li8Fe5O39 (Dutton et al. Inorg. Chem. 2008 47, 11212) using the same techniques. The Mössbauer spectrum reported by Chen et al. has been reinterpreted. The newly refined spectral parameters differ significantly from die published values but are similar to those reported for Nd18Li8Fe5O39). The relative areas of the three components indicate that iron cations occupy the 2a, 8e, and 16i sites in space group ...Pm3n, in disagreement with the model determined from neutron diffraction by Chen et al. in which only the 2a and 8e sites are so occupied. The relationship between Li11Nd18Fe4O39-δ and Ndl8Li8Fe5O39 is discussed, and it is proposed that the sample prepared by Dutton et aL is a kinetic product whereas the sample prepared by Chen et al. is the therrnodynamicalry preferred product. [ABSTRACT FROM AUTHOR]

The A2B2X6X′0.5-type pyrochlore Pb2Ti2O5.4F1.2 is prepared as a single phase by solid state reaction of stoichiometric amounts of PbO, PbF2, and TiO2 (evacuated Pyrex tubes, 873 K, 12 h). [ABSTRACT FROM AUTHOR]