ABSTRACT
Polarized neutron scattering measurements on a single crystal of composition CeIn1Sn2 show a broad, single-ion, spectral response centered on a characteristic energy of approximately 9+/-1 meV at the zone boundary point (0 0 1.5). The zone center spectral response is closely similar in form but has a slightly reduced amplitude, smaller by some 20%. Constant-omega scans show that these intensity modulations, of amplitude approximately 10%, resembling intersite antiferromagnetic correlations, are superimposed on a mean variation that follows the Ce3+, 4f;{1}, single-ion form factor, and are tentatively attributed to q-dependent hybridization of the localized 4f state with the conduction electrons.
ABSTRACT
A favored interpretation of the gamma <--> alpha phase transition in cerium postulates the transformation of the localized 4f state in gamma-Ce to a weakly correlated itinerant 4f band in alpha-Ce. However, results of high-energy neutron inelastic scattering measurements, presented here, show clearly that the magnetic susceptibility response from alpha-Ce follows the Ce3+ form factor despite the large, 30-fold, increase in its spectral width relative to that in gamma-Ce. This observation provides, for the first time, indisputable evidence for the localized character of the 4f state in the alpha phase. The present findings appear consistent with recent calculations combining dynamical mean-field theory with the local density approximation that indicate a strongly correlated 4f state in alpha-Ce. The localized 4f state is also fundamental to the Kondo volume collapse theories for the gamma <--> alpha phase transition in cerium.
ABSTRACT
We present inelastic neutron scattering experiments, performed near the antiferromagnetic quantum critical point in Ce(Ru0.24Fe0.76)2Ge2. Both local and long-range fluctuations of the local moments are observed, but due to the Kondo effect only the latter are critical. We propose a phenomenological expression which fits the energy E, temperature T, and wave vector q dependences of the dynamic susceptibility, describing the non-Fermi liquid E/T scaling found at every q.
ABSTRACT
By combining the results of muon spin relaxation and inelastic neutron scattering in the heavy fermion compounds Ce1-xLaxAl3 (0.0
ABSTRACT
We have used inelastic neutron scattering to determine the magnetic susceptibility chi(q,omega,T) of the non-Fermi-liquid compounds UCu(5-x)Pdx (x = 1,1.5) for energies omega between 0.2 and 2 meV, and for temperatures T between 1.6 and 250 K. Spatial correlations in both UCu4Pd and UCu 3.5Pd1.5 extend over length scales comparable to the unit cell, and display very little temperature dependence. In contrast, the wave vector independent susceptibility diverges as T-->0. We find that the excitations at all q, and for all T and omega accessed display the same type of non-Fermi-liquid omega/T scaling.
