Centro de Química y Materiales de Aragón

Unusual magnetic behaviour is observed in compounds with three Cl ligands in <italic>fac</italic>-mode coordination to dysprosium, cerium and even gadolinium.

Quantum chemical topology analyses provide a new way of understanding the synchronicity of organic reactions.

Abstract Homogeneous polycrystalline Fe x O y nanoparticles were generated by ablation of iron targets in water by nanosecond laser pulses at 532 nm. In ethanol, crystalline core‐shell Fe/Fe x O y structures with size medians around 20 nm were produced. The ablation of FeW x O y targets in water resulted in crystalline hollow shells and homogeneous FeW x O y nanoparticles. In contrast, amorphous core‐shell FeW x O y nanoparticles with a median size of 17 nm were produced in ethanol. The size distribution of both the Fe x O y and the FeW x O y particles showed a slight dependence on fluence and pulse number. This may be related to primary and secondary ablation and modification mechanisms.

-pronucleophiles in the initial oxa-Michael reaction, also leading to the formation of a single stereoisomer under a dynamic kinetic resolution (DKR) process. Importantly, by using β-aryl or β-alkyl substituted α,β-unsaturated substrates as initial Michael acceptors either kinetically or thermodynamically controlled diastereoisomers were formed with high stereoselection through the careful selection of the reaction conditions. Finally, a complete experimental and computational study confirmed the initially proposed DKR process during the catalytic oxa-Michael/Michael cascade reaction and also explained the kinetic/thermodynamic pathway operating in each case.

Abstract This paper reports a new methodology for the coloring of glazed ceramic tiles consisting of the near infrared pulsed laser processing of copper containing oxide coatings prepared by magnetron sputtering. As a second approach, the employ for the same purpose of a novel laser furnace technique is also described. Changing the laser parameters and using the laser furnace to treat the tiles at high temperature during irradiation has resulted in a wide color palette. The optical characterization of the modified tiles by UV ‐Vis spectroscopy has been complemented with their microstructural and compositional analysis by Scanning Electron Microscopy ( SEM ), Transmission Electron Microscopy ( TEM ), and Time Of Flight Secondary Ion Mass Spectrometry (TOF‐SIMS). The chemical composition of the surface was obtained by X‐ray Photoemission Spectroscopy ( XPS ) and its structure determined by X?ray diffraction (XRD). The chemical resistance was characterized by several tests following the norm ISO 10545‐13. Color changes have been attributed to surface microstructural and chemical transformations that have been accounted for by simple models involving different ablation, melting, diffusion, and segregation/agglomeration phenomena depending on the laser treatments employed.

Summary form only given. Yttria stabilised zirconium oxide (YSZ) is a very important class of ceramic with unique mechanical and electrochemical properties. For this reason, YSZ is been widely used in oxygen sensors and solid oxide fuel cells (SOFC). Among the different SOFC configurations, the electrolyte-supported one exhibits better mechanical robustness and resistance to redox cycles than the electrode-supported configuration. However, its main inconvenience is that electrolyte-supported cells are prepared over 100-300 μm thick electrolytes and, as a consequence, they are designed to operate at high temperatures to reduce its ohmic resistance, typically about 900°C for YSZ electrolytes.The ability of YSZ ceramic to withstand precision machining would allow a different alternative, using laser machining, to prepare thinner self-supporting ionic conducting membranes. In the last few years, laser technology has shown very unique results for materials engraving. It allows a cost-efficient production for the fabrication of high quality ceramic parts with excellent shaping, accuracy and surface finishing [1]. The laser machining procedure yields to the fabrication of ceramics membranes from a thick and sintered ceramic plate. The original thick plate is engraved in the central part to obtain a thin region (around 20 μm), which is the electrochemically active area, while the surrounding part remains thick and acts as a mechanical support giving the membranes outstanding thermomechanical integration [2].