Reticular Imine-Linked Coordination Polymers Based on Paddlewheel Diruthenium/Dirhodium Nodes: Synthesis and Metal-Site Dependent Photocatalytic Reduction of CO.

The paddlewheel-type dimetal core ([M]) is a ubiquitous motif in the nodes in coordination polymers (CPs) and metal-organic frameworks (MOFs). However, their preparation has relied on ligand-substitution-labile metal ions owing to challenges associated with crystallization. Consequently, examples featuring ligand-substitution-inert metal ions, such as Ru or Rh, are scarce.

Microstructures and Interface Magnetic Moments in MnVAl/Fe Layered Films Showing Exchange Bias.

Heusler alloys are a material class exhibiting various magnetic properties, including antiferromagnetism. A typical application of antiferromagnets is exchange bias that is a shift of the magnetization curve observed in a layered structure consisting of antiferromagnetic and ferromagnetic films. In this study, a layered sample consisting of a Heusler alloy, Mn2VAl and a ferromagnet, Fe, is selected as a material system exhibiting exchange bias.

Beating Thermal Coarsening in Nanoporous Materials via High-Entropy Design.

Controlling the feature sizes of 3D bicontinuous nanoporous (3DNP) materials is essential for their advanced applications in catalysis, sensing, energy systems, etc., requiring high specific surface area. However, the intrinsic coarsening of nanoporous materials naturally reduces their surface energy leading to the deterioration of physical properties over time, even at ambient temperatures.

Evaluation of spatial and temporal resolution on in situ annealing aberration-corrected transmission electron microscopy with proportional-integral-differential controller.

The in situ annealing observation in transmission electron microscope (TEM) is one of the effective methods for imaging thermally induced microstructural changes. For applying this dynamical characterization to bulk samples fabricated by ion-milling, electro-polishing or focused ion beam (FIB) mill, it is generally needed to use a heating-pot type system. We here report an initial trial to improve the spatial and temporal resolution during the in-situ annealing observation of bulk samples using a spherical aberration corrected (AC) TEM with a new thermal control unit.

Atomic and nanoscale imaging of a cellulose nanofiber and Pd nanoparticles composite using lower-voltage high-resolution TEM.

We have examined the advanced application of transmission electron microscopy (TEM) for the structural characterization of a composite of cellulose nanofiber (CNF) and palladium (Pd) nanoparticles. In the present study, we focused on electron-irradiation damage and optimization of high-resolution TEM imaging of the composite. The investigation indicates that the CNF breaks even under low-electron-dose conditions at an acceleration voltage of 200 kV.

The demonstration of significant ferroelectricity in epitaxial Y-doped HfO2 film.

Ferroelectricity and Curie temperature are demonstrated for epitaxial Y-doped HfO2 film grown on (110) yttrium oxide-stabilized zirconium oxide (YSZ) single crystal using Sn-doped In2O3 (ITO) as bottom electrodes. The XRD measurements for epitaxial film enabled us to investigate its detailed crystal structure including orientations of the film. The ferroelectricity was confirmed by electric displacement filed - electric filed hysteresis measurement, which revealed saturated polarization of 16 μC/cm(2).

Thermally stable dielectric responses in uniaxially (001)-oriented CaBi4Ti4O15 nanofilms grown on a Ca2Nb3O10- nanosheet seed layer.

To realize a high-temperature capacitor, uniaxially (001)-oriented CaBi4Ti4O15 films with various film thicknesses were prepared on (100)cSrRuO3/Ca2Nb3O10(-) nanosheet/glass substrates. As the film thickness decreases to 50 nm, the out-of-plane lattice parameters decrease while the in-plane lattice ones increase due to the in-plane tensile strain. However, the relative dielectric constant (εr) at room temperature exhibits a negligible degradation as the film thickness decreases to 50 nm, suggesting that εr of (001)-oriented CaBi4Ti4O15 is less sensitive to the residual strain.

Three-Dimensional Imaging of Dislocations in a Ti-35mass%Nb Alloy by Electron Tomography.

We have studied three-dimensional (3D) configurations of dislocations in the β phase of a Ti-35mass%Nb alloy by means of single-axis tilt tomography using bright-field scanning transmission electron microscopy (BF-STEM). To visualize dislocations, the 0 systematic reflections were excited throughout tilt-series acquisition with the maximum tilt angle of 70°. Dislocations in the β grains were clearly reconstructed by the weighted back-projection algorithm.

Diffraction contrast analysis of 90° and 180° ferroelectric domain structures of PbTiO thin films.

The ferroelectric domain structure of a PbTiO thin film on (100) SrTiO has been investigated by transmission electron microscopy (TEM). Two types of a-domain were found: one extended through the film to the surface and another comprised small a-domains confined within the film. Dark-field TEM (DFTEM) observation revealed that 180° domains formed near the substrate and stopped their growth 100 nm away from the substrate.

Polymers of 2-methacryloyloxyethyl phosphorylcholine truly work as cell membrane mimic?

We have prepared several types of polymers derived from 2-methacryloyloxyethyl phosphorylcholine (MPC) to evaluate whether polymers of MPC work as cell membrane mimic or not. We firstly applied capturing test of target proteins of 4-carboxybenzenesulfonamide (Sul) or ibuprofen (Ibu) as a probe. As the results, the rather hydrophilic polymers based on MPC were able to suppress non-specific binding proteins as expected.

Direct observation of a surface induced disordering process in magnetic nanoparticles.

We present experimental evidence of surface induced disordering at magnetic FeCoPd nanoparticles during the L1(0)-A1 phase transition using high-resolution aberration-corrected electron microscopy and strain mapping. In situ electron diffraction studies show a narrow temperature range of fully ordered L1(0) structure. The order-disorder transition is size dependent and induces strong lattice deformation in outer part of the nanocrystals.

HAADF-STEM study on the early stage of precipitation in aged Al-Ag alloys.

We report on the structure of Ag precipitates in aged Al-Ag alloys using transmission electron microscopy and high-angle annular detector darkfield scanning transmission electron microscopy (HAADF-STEM). Irregularly shaped small Ag particles of 1-2 nm dominate the alloy annealed at 140 degrees C for 10 h. These particles are present also within large precipitates (10-50 nm), which are often characterized by their {100} and {110} facets.