Abstrakt
Hydrogen exposure of Tb2Pd2Mg crystallizing in the tetragonal Mo2FeB2 structure results in the absorption 8 +/- 1 H/f.u. The absorption is not reversible and leads to a structure transition yielding a new structure type (Pearson symbol O140, space group Fmmm).
Tb2Pd2Mg is an antiferromagnet with TN approximate to 60 K showing 2 metamagnetic transitions. Upon hydrogenation the susceptibility cusp related to AF ordering disappears and the susceptibility increases monotonously with decreasing temperature.
Magnetic remanence, which starts to develop below 20-25 K, can be attributed to a randomness in H sites occupancy.