Abstract
The cubic compound exhibits heavy fermion behavior with a high extrapolated value of the electronic specific heat, as . The specific heat does not exhibit any sign of long range magnetic ordering down to . In order to understand the origin of the high value of and the nature of the electrons of this compound, we have carried out neutron diffraction, low-field magnetic susceptibility, muon spin relaxation, and inelastic neutron scattering measurements on . Our susceptibility results show that for temperatures between 20 and , a power law behavior is exhibited, with . Below , the susceptibility is almost temperature independent, again without any sign of magnetic ordering down to the lowest available temperature . The muon spin relaxation measurements reveal that below , the electronic relaxation rate strongly increases without any loss of muon initial asymmetry, indicating the presence of low energy spin fluctuations as an explanation for the high value of in . Heat capacity data reveal a behavior, indicating that may exhibit non-Fermi-liquid behavior close to a quantum critical point. Our inelastic neutron scattering results reveal a broad crystal field excitation centered at , indicating the presence of strong hybridization between the and the conduction electrons, which is consistent with the observed high value of the paramagnetic Curie temperature .
3 More- Received 16 May 2007
- Accepted 6 September 2007
DOI:https://doi.org/10.1103/PhysRevB.76.174439
©2007 American Physical Society