Hydrogen-induced new functions in sub-nano lattice matter

This paper includes some results of "Hydrogen-Induced New Functions in Sub-Nano Lattice Matters" accomplished by MEXT's program "Elements strategy Project". In the 21st century, the era concerning about environment, this research achieve- ment utilizing hydrogen as the technology for strengthening alloys will be expected to make a breakthrough in the metal heat- treatment and processing technology as the new environmental conscious process. Hydrogen heat-treatments for grain-size refinements of alloys were performed. The grain size of Cu-3 mass%Ti alloy turned into about 20~50 nm after hydrogenation and dehydrogenation treatment. Moreover, grain-size refined Ti-based alloy showed large super-elastic elongation. On the other hand, hydrogen induced functions in the alloys were also investigated. Hydrogen transmitting films with Pd nanogranular parti- cles dispersed in ceramic material were developed as attachment of metal-hydride switchable mirrors. Metamagnetism transition temperature (Tc) could be increased by hydrogen introduction in La (Fe _xSi _1-x) Pd/Pt core-shell type nano-particles were also investigated.