YNi4B is a paramagnetic compound with the susceptibility equal to 2.7??10-6 emu/g at 5 K. From
the low-temperature specific heat, values of 458 K for the Debye temperature and 14.1 mJ/K2 mol for the
coefficient of the electronic specific heat are obtained. GdNi 4B is ferromagnetic below Tc=35.0 K where
the ?-type anomaly is observed in the specific heat. Magnetic and specific-heat measurements provide strong
evidence that the 3d band in YNi 4B and GdNi4B is completely filled.
