Find in Library

A hydride of Yb₂Pd₂Sn could be synthesized with approximately 2 H atoms per f.u. The hydrogenation leads to a volume expansion while preserving the tetragonal symmetry (<i>P</i>4/<i>mbm</i>). The lattice reaction is strongly anisotropic, and the 5% expansion in <i>c</i> is partly compensated by the 0.5% compression in <i>a</i>. The hydride is paramagnetic at least down to 0.5 K. Yb remains at or very close to the 3+ (4<i>f</i>¹³) state, as in Yb₂Pd₂Sn. Specific heat <i>C</i>/<i>T</i> vs. <i>T</i> shows an upturn existing already in Yb₂Pd₂Sn, but it is much more pronounced in the hydride (1.8 J/mol f.u. K² for <i>T</i> → 0, i.e., more than twice higher than in its precursor). This is interpreted as lowering the Kondo temperature due to H bonding.