Excess heat capacity in magnetically ordered Ce heavy fermion metals

Abstract

We study the magnetic heat capacity of a series of magnetically ordered Ce-based heavy fermion materials, which show an anomalous $T^3$ heat capacity in excess of the phonon contribution in many materials. For compounds for which magnon models have been worked out, we show that the local-moment magnon heat capacity derived from the measured magnon spectra underestimates the experimental specific heat. The excess heat capacity reveals increasing density of states with increasing energy, akin to a pseudogap. We show that this anomalous temperature-dependent term is not associated with proximity to a quantum critical point (QCP), but is strongly correlated with $T_N$, indicating the anomalous excitations are governed by the magnetic exchange interaction. This insight may hold key information for understanding magnetically ordered heavy fermions.

5 pages, 4 figures

References in corpus (11)

• Heavy Fermions and Quantum Phase Transitions
• Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5
• Hidden Order Behaviour in URu2Si2 (A Critical Review of the Status of Hidden Order in 2014)
• Multiple quantum phase transitions and superconductivity in Ce-based heavy fermions
• The magnitude of the magnetic exchange interaction in the heavy fermion antiferromagnet CeRhIn${}_5$
• Giant Uniaxial Anisotropy in the Magnetic and Transport Properties of CePd5Al2
• Low-energy magnetic response of the noncentrosymmetric heavy-fermion superconductor CePt3Si studied via inelastic neutron scattering
• Spin-liquid signatures in the quantum critical regime of pressurized CePdAl
• Relaxing Kondo screened Kramers-doublets in CeRhSi${}_3$
• Specific heat of CeRhIn${}_5$ in high magnetic fields: Magnetic phase diagram revisited
• A microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn${}_3$