Temperature dependence of low-energy phonons in magnetic nonsuperconducting TbNi2B2C

We report temperature dependence of low-energy phonons in magnetic nonsuperconducting TbNi2B2C single crystals measured by inelastic neutron scattering. We observed a low-temperature softening and broadening of two phonon branches, qualitatively similar to that previously reported for superconducting RNi2B2C (R= rare earth, Y) compounds. This result suggests that the superconductivity in TbNi2B2C compounds is absent not because of a weak electron-phonon coupling but as a result of pairbreaking due to magnetism.