Kobe University Repository : Kernel タイトル Tit le Heat Evolut ion from Pd Nano-powders Exposed to High-pressure Hydrogen Isotopes and Associated Radiat ion Measurements

Using a twin system for hydrogen absorption, experiments on heat evolution and charged particle generation by D2 (H2) gas absorption in nano-sized Pd powders were done for the 0.1 μm. Pd powder, the Pd-black, and the mixed oxides of Pd·Zr, Pd·Ni·Zr and Ni·Zr. It has been found that the D(H)/Pd loading ratio and the absorption energy per D (H) is an increasing function of fineness of the sample surface. The Pd·Zr oxide nano-composites showed anomalously large energies of hydrogen isotope absorption as well as large loading ratio in the phase of deuteride/hydride formation. Although the samples were deteriorated by the repeated baking-hydrogenation cycles, an artificial oxidation of the PZ and the PNZ samples recovered the excellent original performances, and gave hydride formation energies of 1.5–2.3 eV/D and 1.5–2.0 eV/H, which are anomalously high compared with values for bulk Pd metal. In the second phase after the deuteride formation, the Pd·Zr and Pd·Ni·Zr oxide composites charged exclusively with D2 sometimes gave significantly positive output, which should be subjected to repeated investigation. Nuclear reaction products including energetic charged-particles for a possible cause of the phenomena were examined using a variety of nuclear diagnostics. © 2011 ISCMNS. All rights reserved.