Crystal-field spectrum and linewidths in the heavy-fermion system PrInAg2

The heavy-fermion intermetallic compound PrInAg2 has been studied by means of inelastic neutron scattering. In agreement with a previous study, there is clear evidence from both the excitation energies and relative intensities that the crystal-electric-field ground state is the Gamma(3) nonmagnetic, non-Kramers doublet, and this, together with enhanced thermodynamic properties at low temperatures, indicates that PrInAg2 is a candidate quadrupolar Kondo material. In addition to the Gamma(3)-Gamma(4) and Gamma(3)-Gamma(5) excitations, which are seen at low temperature, we have observed the other two allowed transitions, Gamma(4)-Gamma(1), and Gamma(4)-Gamma(5), which are visible when the Gamma(4) triplet becomes thermally populated. Within the Lea-Leask-Wolf parametrization scheme, we obtain W = -0.111 +/- 0.006 meV and x = -0.079+/-0.037, values that are similar to but slightly different from those previously reported. No magnetic quasielastic scattering is seen, down to similar to 90 mu eV, and this provides further evidence that the heavy-fermion behavior is unconventional and has a nonmagnetic origin. However, bath the Gamma(3)-Gamma(4) and Gamma(3)-Gamma(5) levels are broadened significantly and to differing degrees. Possible sources of this broadening are discussed.