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During the past decade, CoFe2O4 (hard)/Co–Fe alloy (soft) magnetic nanocomposites have been routinely prepared by partial reduction of CoFe2O4 nanoparticles. Monoxide (i.e., FeO or CoO) has often been detected as a byproduct of the reduction, although it remains unclear whether the formation of this phase occurs during the reduction itself or at a later stage. Here, a novel reaction cell was designed to monitor the reduction in situ using synchrotron powder X-ray diffraction (PXRD). Sequential Rietveld refinements of the in situ data yielded time-resolved information on the sample composition and confirmed that the monoxide is generated as an intermediate phase. The macroscopic magnetic properties of samples at different reduction stages were measured by means of vibrating sample magnetometry (VSM), revealing a magnetic softening with increasing soft phase content, which was too pronounced to be exclusively explained by the introduction of soft material in the system. The elemental compositions of the constituent phases were obtained from joint Rietveld refinements of ex situ high-resolution PXRD and neutron powder diffraction (NPD) data. It was found that the alloy has a tendency to emerge in a Co-rich form, inducing a Co deficiency on the remaining spinel phase, which can explain the early softening of the magnetic material. ; The authors thank financial support from the European Commission through the NANOPYME (FP7-SMALL-310516) and AMPHIBIAN (H2020-NMBP-2016-720853) projects. Financial support from the Danish National Research Foundation (Center for Materials Crystallography, DNRF-93) and the Danish Center for Synchrotron and Neutron Science (DanScatt) is gratefully acknowledged. Parts of this research were carried out at PETRA III at DESY, a member of the Helmholtz Association (HGF). We thank Jozef Bednarcik for assistance in using beamline P02.1. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. This project has received funding from the European Union's Seventh Framework Programme for research, technological development, and demonstration under the NMI3-II Grant 283883. ; Peer reviewed

The title compound was synthesized by 2:1 condensation between adamantan-1-ylamine and benzene-1,4- dicarbaldehyde in n-BuOH and produced a good yield 87% of new bis Schiff base. The compound skeleton was affirmed by FTIR, 1H NMR, LC-MS, and X-ray powder diffraction. The structure was solved by a parallel tempering process and refined by using Rietveld refinement. Two adamantan-1-ylimino groups are connected in the anti-positions to the planar central 1,4-dimethylbenzene group. All rings of the adamantyl group possess normal chair conformation.

Lithium-ion batteries currently equip portable electronic devices, such as smartphones and laptops, and are the choice to power electric vehicles. The scarcity of raw materials in nature, however, has required the development of new technologies and the ternary lithium compound LiNi1/3Mn1/3Co1/3O2 has stood out as an alternative for replacing part of the cobalt in LiCoO2 by nickel and manganese, which are more abundant, reducing the electrode's cost. The sol-gel route for synthesis of ternary electrode materials has been widely used, but it faces problems of volumetric expansion due to the decomposition of organic material during calcination. To improve the synthesis of the ternary compound, a modified sol-gel route with control of the heating kinetics in the pre-calcination step and without pH control was investigated in this study. The compound was analyzed by X-ray diffraction, Rietveld refinement, Fourier transform infrared absorption spectroscopy, and Raman that showed the purification of the ternary phase with appropriate crystallinity for application as electrode in batteries from 700 ºC. In conclusion, ternary synthesis with rate control during heat treatment may be a useful alternative for industrial scale-up production.

A simultaneous analysis of the crystallite size and strain of xNiO·(1 - x)GDC nanopowders prepared in stoichiometric proportions of x = 0, 0.1, 0.2. to 1 was performed by a self-sustained combustion (SC) process and calcination of the thus-synthesized nanopowders at 600 °C. The nanopowders were examined by powder X-ray diffraction (XRD) pattern using two approaches: integral breadth of multiple peaks (multi-line) with Pearson VII (PVII), and pattern analysis of powders through total adjustment of the diffraction peaks with the double-Voigt (V-V) method. The synthesis route and stoichiometric variation allowed a quantitative study using the global setting profile with Rietveld refinement and semi-quantitative analysis by X-ray fluorescence (XRF) of nickel oxide (NiO) and gadolinium doped ceria (GDC) phases in the as-prepared and the calcined samples. The investigation of the microstructures of the nanopowders was further supported by high-resolution transmission electron microscopy (HR-TEM) and scanning electronic microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). ; Thanks to National Doctoral Scholarship (No. 63130223) for Foreigners in Chile CONICYT, Government of Chile, Santiago for financing to conduct and complete this work. ; Peer Reviewed

The first fluorination of the cuspidine-related phases of Ln4(Al2O7□)O2 (where Ln = Sm, Eu, Gd) is reported. A low-temperature reaction with poly(vinyl-idene difluoride) lead to the fluorine being substituted in place of oxygen and inserted into the vacant position between the dialuminate groups. X-ray photoelectron spectroscopy shows the presence of the F 1s photoelectron together with an increase in Al 2p and rare-earth 4d binding energies supporting F incorporation. Energy-dispersive X-ray spectroscopy analyses are consistent with the formula Ln4(Al2O6F2)O2, confirming that substitution of one oxygen by two fluoride atoms has been achieved. Rietveld refinements show an expansion in the cell upon fluorination and confirm that the incorporation of fluoride in the Ln4(Al2O7□)O2 structure results in changes in Al coordination from four to five. Thus, the isolated tetrahedral dialuminate Al2O7 groups are converted to chains of distorted square-based pyramids. These structural results are also discussed based on Raman spectra. ; This research was funded by the Ministerio de Economía, Industria y Competitividad (MAT2016-76739-R) (AEI/FEDER, UE), and Departamento de Educación of the Basque Government (IT-630–13). The authors thank SGIker of UPV/EHU for technical and personnel support. A. Mora´nRuiz thanks UPV/EHU for funding. ; Peer reviewed

Highly sodium deficient Na0.6NbO3 (NN) ceramics were prepared and characterized. Their mean structure could be described by a mixture of the predominant P polymorph (S.G. Pbma) and the Q phase (S.G. P2(1)ma), at room temperature, as deduced from Rietveld refinements of Powder X-ray diffraction and Raman scattering data. Besides, microstructural and compositional heterogeneity was evidenced from HRTEM and XPS analyses. Dielectric measurements on this highly vacancies-containing NN material indicated a hysteretic transition taking place at similar to 12 and -18 degrees C on the heating and cooling regimes, respectively. This means a considerable shift to lower temperatures of the transition temperatures concerning the P/Q transformations previously described for the NaNbO3 material. At an intermediate frequency of 10 kHz, maximum permittivity and tangent loss values of epsilon' = 1250 and tg delta = 2 were obtained on heating, whereas lower values of epsilon' = 65 and tg delta = 0.04 were displayed on cooling regime. These anomalies were interpreted in terms of ferrolectric-antiferroelectric-paralectric phase-transitions implying a PTCR behavior within certain temperature range. This response, observed in this complex material for the first time, has interesting implications for the possible application of NN ceramics in sensing and dielectric materials fields. ; FONDEQUIP EQM140142 Spanish MINECO MAT2017-84118-C2-2-R Ministerio de Ciencia, Innovación y Universidades RTI2018-099668-BC22 Junta de Andalucia European Union (EU) UMA18-FEDERJA-126

Glass-ceramic materials with composition 0.9Nd3+–80SiO2–20LaF3 were successfully obtained and further heat-treated at 450 °C for 6 h. Stable and homogeneous LaF3 nanoparticle suspensions with and without Nd3+ were first prepared by a chemical route, incorporating polyvinylpyrrolidone (PVP) as dispersant. The suspensions were then concentrated and characterised by XRD, HRTEM and zeta potential, confirming that LaF3 crystallises as the only phase, with particle size around 16 nm. The suspensions were incorporated in a silica sol to obtain a 0.9Nd3+–20LaF3–80SiO2 particulate sol, xerogel and glass-ceramic. HRTEM confirmed the homogeneous incorporation of the doped nanocrystals into the SiO2 matrix without modification of the nanoparticle structure. Rietveld refinement was used to determine the crystallinity and quantity of LaF3 nanoparticles present in the glass-ceramic after treatment of the particulate sol at 450 °C for 6 h. Luminescence measurements of near infrared Nd3+ ion emissions in the lanthanum fluoride nanoparticles and SiO2–LaF3 glass-ceramic showed well-structured emission spectra with lifetimes similar to those of theoretical Nd+3 in LaF3 crystals. ; The authors acknowledge the financial support from MINECO under projects MAT2017-87035-C2-1-P/-2-P (AEI/FEDER, UE), Basque Country University GIU17/014 and Basque Government PIBA2018-24. This article is a part of the dissemination activities of the project FunGlass, which has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no. 739566. The authors also acknowledge the support of the Transmission Electron Microscope (TEM) service of the Institute of Catalysis and Petrochemistry (CSIC). ; Peer reviewed