  The electron-quasiparticle interaction (EQI) spectral function has been
measured for $\rm DyNi_2B_2C$ in the normal state at low temperatures by means
of point-contact spectroscopy (PCS). A low-frequency peak is found around
$eV\sim 5\ meV$. It becomes measurable at $T_m^*\simeq 15\ K$ and grows in
intensity with constant width as the temperature is lowered. We argue that this
peak arises from the strong interaction of conduction electron with coupled
crystal-electric-field-phonon excitations whose branches cross at low energy.
The comparison with PC spectra for $\rm HoNi_2B_2C$ suggests that a similar
peak also exists for this compound. The magnitude of the point-contact EQI
parameter $\lambda_{PC}$ for $\rm DyNi_2B_2C$ is estimated. $\copyright$2000
Published by Elsevier Science B.V. All rights reserved.
