Susumu Imashuku

The effects of various cations (, , , , , , , , , , and ) were examined as dopants into the B site of perovskite barium zirconate. The solubility of In, Yb, Tm, Er, and Ho, whose ionic radii are close to that of zirconium ion, into the B site is more than 0.075 at . In contrast, when there is a large difference of ionic radii between trivalent cations (, , , and ) and zirconium ion, the solubility of trivalent cations into barium zirconate is less than . The microstructure of sintered pellets an

Scandium and yttrium co-doped barium zirconate [ ] have been investigated in terms of phase relationship, microstructures, and electrical conductivity. The bulk conductivity of the scandium and yttrium co-doped barium zirconate increased with the dopant ratio of yttria. had the highest grain-boundary conductivity among the scandium and yttrium co-doped barium zirconates in this study. But, , , , and consisted of a single cubic perovskite phase at 1600°C and their densities of grain-boundary were

Typical microstructures of sintered for at were mixtures of larger and smaller grains. Well-grown and homogeneous grains of were observed by adding an extra amount of barium oxide from stoichiometric composition or extending the sintering time to . Such an extra amount of barium oxide is expected to decrease chemical stability in a wet atmosphere, and we observed the precipitation of yttria after sintering. However, we did not meet such difficulties in sintering . Large and uniform grains were o

Scanning electron microscope – cathodoluminescence (SEM ‐ CL) analysis was carried out for the rapid phase identification of a single particle with the size of approximately 100 µm consisting of alumina (Al 2 O 3 ) and spinel (MgAl 2 O 4 ) phases. We selected this particle as the analyte because Al 2 O 3 and MgAl 2 O 4 are typical inclusions in steel, and their identification is important for steel production. Samples were prepared by pressing a mixture of Al 2 O 3 and magnesia (MgO) powders hea

Identification of nitride inclusions such as boron nitride (BN) and aluminum nitride (AlN) is important in the steelmaking industry because BN inclusions deteriorate the creep strength of ferritic heat‐resistant steel, and AlN inclusions cause transverse cracking in twin‐induced‐plasticity steel. The conventional method employed for the analysis of such inclusions in steel comprises both optical microscopy and electron probe microanalysis (EPMA), which is the time‐consuming. The aim of this stud

Increasing oxygen permeation from oxide membranes can enable the development of next-generation power generation technologies with high efficiency and reduced CO2 mission. Here we introduce a new approach to design oxygen permeation membranes by covering the surfaces of pure oxygen-ion conductors with porous precious metal (Au and Ag) network or MIECs (LNO and LSCF). Oxygen permeation flux was enhanced by greatly by coating porous silver on the whole surface of pure oxygen ion-conducting membran