One-step preparation, microstructure and properties of WRe/TZM gradient material for X-ray tube of CT scanner

Iridium-containing NaTaO3 is produced using a one-step hydrothermal crystallisation from Ta2O5 and IrCl3 in an aqueous solution of 10 M NaOH in 40 vol% H2O2 heated at 240 °C. Although a nominal replacement of 50% of Ta by Ir was attempted, the amount of Ir included in the perovskite oxide was only up to 15 mol%. The materials are formed as crystalline powders comprising cube-shaped crystallites around 100 nm in edge length, as seen by scanning transmission electron microscopy. Energy dispersive X-ray mapping shows an even dispersion of Ir through the crystallites. Profile fitting of powder X-ray diffraction (XRD) shows expanded unit cell volumes (orthorhombic space group Pbnm) compared to the parent NaTaO3, while XANES spectroscopy at the Ir LIII-edge reveals that the highest Ir-content materials contain Ir4+. The inclusion of Ir4+ into the perovskite by replacement of Ta5+ implies the presence of charge-balancing defects and upon heat treatment the iridium is extruded from the perovskite at around 600 C in air, with the presence of metallic iridium seen by in situ powder XRD. The highest Ir-content material was loaded with Pt and examined for photocatalytic evolution of H2 from aqueous methanol. Compared to the parent NaTaO3, the Ir-substituted material shows a more than ten-fold enhancement of hydrogen yield with a significant proportion ascribed to visible light absorption.

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A Versatile Approach to Access Trimetallic Complexes Based on Trisphosphinite Ligands

Molecules ◽

10.3390/molecules25030593 ◽

2020 ◽

Vol 25 (3) ◽

pp. 593

Author(s):

Juan Miranda-Pizarro ◽

Macarena G. Alférez ◽

M. Dolores Fernández-Martínez ◽

Eleuterio Álvarez ◽

Celia Maya ◽

...

Keyword(s):

Coordination Chemistry ◽

Late Transition Metal ◽

X Ray Diffraction ◽

X Ray ◽

Full Characterization ◽

Metal Precursors ◽

Straightforward Method ◽

One Step ◽

Late Transition

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.

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Effect of the BSCCO superconducting properties by tiny Y2O3 addition

Modern Physics Letters B ◽

10.1142/s0217984916503280 ◽

2016 ◽

Vol 30 (26) ◽

pp. 1650328

Author(s):

Yan Dong ◽

Aimin Sun ◽

Bin Xu ◽

Hongtao Zhang ◽

Meng Zhang

Keyword(s):

Volume Fraction ◽

Superconducting Properties ◽

X Ray Diffraction ◽

Critical Transition Temperature ◽

Solid State Reaction Technique ◽

X Ray ◽

Oxide Addition ◽

One Step ◽

Step Transition ◽

Y2o3 Addition

In this paper, the effect of tiny Y2O3 addition in (Bi,[Formula: see text]Pb)-2223 superconductor prepared by solid state reaction technique was studied. The properties of samples have been investigated via X-ray diffraction (XRD), resistance–temperature ([Formula: see text]–[Formula: see text]) curve, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). XRD data indicated that all samples are multiphase and the major phases are high-temperature phases and low-temperature phases. The volume fraction of (Bi,[Formula: see text]Pb)-2223 is not great change with tiny Y2O3 addition. All samples exhibit superconducting phase with the critical transition temperature and one-step transition, however, the transition width was decreased with the Y2O3 addition up to 0.04 wt.% and sharp increased with the excessive oxide addition. SEM pictures show that the Y2O3 appeared on the flake-type grains surface obviously, but the number and size of the hole between grains are decreased in the 0.04 wt.% addition.

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One Step Synthesis and Characterization of Zirconia-Graphene Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.600.174 ◽

2012 ◽

Vol 600 ◽

pp. 174-177 ◽

Cited By ~ 1

Author(s):

Jian Fei Xia ◽

Zong Hua Wang ◽

Yan Zhi Xia ◽

Fei Fei Zhang ◽

Fu Qiang Zhu ◽

...

Keyword(s):

Synthesis And Characterization ◽

Two Dimensional ◽

X Ray Diffraction ◽

X Ray ◽

Graphene Composite ◽

Transmission Electron ◽

One Step ◽

Ft Ir ◽

Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

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