The preparation and crystallographic characterization of two new types of ternary metal hydrides

Abstract

Ternary metal hydrides of thorium with zirconium or titanium have recently been prepared and identified. One of these compounds, ThZr2H7±x, has the cubic C15 type of structure. This hydride shows a high hydrogen density, e.g., 6.7 to 7.7 x 1022 hydrogen atoms per cu cm i.e., NH 6.7 to 7.7) and relatively low equilibrium hydrogen pressures at elevated temperatures. The second new type of hydride is ThTi2H6±x which crystallizes with the hexagonal C14 structure. This hydride also has a high hydrogen density of 8.0 to 8.8 x 1022 hydrogen atoms per cu cm and is relatively stable at elevated temperatures. High hydrogen density (high NH) and low equilibrium hydrogen pressure are a generally sought after combination of characteristics for hydrides to be used in nuclear reactors and in other applications. Accordingly, these two new kinds of hydrides and their possible analogs may be of future use in a variety of applications.