Hydrogen influence in the UNiAl-UNiGa system: Structure and magnetism

Hydrogen absorption studies on UNiAl1-xGax were performed as part of our investigation of UTX compounds. The whole series crystallizes in the hexagonal structure of the ZrNiAl type (s.g. P-62m). The amount of hydrogen absorbed has a decreasing tendency with increasing Ga concentration. Studies of the temperature dependence of magnetic susceptibility indicate certain increase of the critical temperature of magnetic ordering in the hydrides but the increment becomes smaller with increasing Ga concentration as a result of smaller H absorption and concomitant changes in the crystal structure.