Synthesis and reactivity of single-phase BeTi intermetallic compounds

Kim, Jae-Hwan; Iwakiri, Hirotomo*; Furugen, Tatsuaki*; Nakamichi, Masaru

To investigate feasibility for application of BeTi as a neutron multiplier as well as a refractory material, single-phase BeTi intermetallic compounds were synthesized using an annealing heat treatment of the starting powder and a plasma sintering method. Scanning electron microscopic observations and X-ray diffraction measurements reveal that the single-phase BeTi compounds were successfully synthesized. We examined the reactivity of BeTi with 1% HO and discovered that a larger stoichiometric amount of Ti resulted in the formation of TiO on the surface at high temperatures. This oxidation may also contribute to an increase in both weight gain and generation of H. This suggests that the formation of the Ti-depleted BeTi layer as a result of oxidation facilitates an increased reactivity with HO. To evaluate the safety aspects of BeTi, we also investigated the hydrogen positions and solution energies based on the first principle. The calculations reveal that there are 10 theoretical sites, where 9 of these sites have hydrogen solution energies with a positive value (endothermic) and 1 site located at the center of a tetrahedron comprising two Be and two Ti atoms gives a negative value (exothermic).