No abstract

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry-Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-DECIGO first and finally DECIGO in 2024.

No abstract

Uniform spheres of (Y 1-x Gd x ) 2 O 3 (x ) 0-1) are valuable for applications in phosphors, in optical ceramics fabrication, and in combinatorial synthesis. We made in this work such particles by thermal decomposition of precursors synthesized via homogeneous precipitation. Growth kinetics and composition evolution of the precursor spheres were investigated in detail, and it was identified for the first time that (1) differential nucleation occurs with regard to Y and Gd, and as a result concentration gradients exist within each precursor particle of the mixed Y/Gd system (more Gd and less Y from particle surface to the core), (2) average particle size of the colloidal sphere is inversely proportional to nucleation density and is significantly affected by the Gd content, (3) growth of the colloidal spheres is diffusion controlled and follows the cubic-root law, and (4) the dried precursor spheres directly convert to cubic-structured (Y 1-x Gd x ) 2 O 3 (x ) 0-1) oxides at 1000 °C while largely retaining their morphologies. The resultant oxides exhibit linearly increased lattice parameters and linearly decreased bandgaps (from 5.57 eV for Y 2 O 3 to 5.20 eV for Gd 2 O 3 ) with increased Gd addition. The findings of this work may have wide implications to other mixed materials systems.