INELASTIC NEUTRON SCATTERING FROM THE SUPERCONDUCTING HEAVY-FERMION COMPOUND UBe13 AND THE REFERENCE SYSTEM ThBe13.

The authors present results of inelastic neutron-scattering on polycrystalline samples of the heavy-fermion compound UBe//1//3 and for ThBe//1//3 as a reference system. They analyze these data on the basis of a Born-von-Karman model. Their results give clear evidence for the existence of an Einstein-mode-like oscillator around 13 mev for both compounds, independently of temperature. From the deduced phonon density of states, the authors calculate the lattice contribution to the low-temperature heat capacity. It is found to be small compared to the total specific heat measured for UBe//1//3.