Specific heat of CeRhIn${}_5$ in high magnetic fields: Magnetic phase diagram revisited

Abstract

CeRhIn${}_5$ is a prototypical antiferromagnetic heavy-fermion compound, whose behavior in a magnetic field is unique. A magnetic field applied in the basal plane of the tetragonal crystal structure induces two additional phase transitions. When the magnetic field is applied along, or close to, the $c$ axis, a new phase characterized by a pronounced in-plane electronic anisotropy emerges at $B^{\ast }\approx$ 30 T, well below the critical field, $B_c\simeq$ 50 T, to suppress the antiferromagnetic order. The exact origin of this new phase, originally suggested to be an electronic-nematic state, remains elusive. Here we report low-temperature specific-heat measurements in CeRhIn${}_5$ in high static magnetic fields up to 36 T applied along both the $a$ and $c$ axes. For fields applied along the $a$ axis, we confirmed the previously suggested phase diagram, and extended it to higher fields. This allowed us to observe a triple point at $\sim$ 30 T, where the first-order transition from an incommensurate to commensurate magnetic structure merges into the onset of the second-order antiferromagnetic transition. For fields applied along the $c$ axis, we observed a small but distinct anomaly at $B^{\ast }$, which we discuss in terms of a possible field-induced transition, probably weakly first-order. We further suggest that the transition corresponds to a change of magnetic structure. We revise magnetic phase diagrams of CeRhIn${}_5$ for both principal orientations of the magnetic field based entirely on thermodynamic anomalies.

6 pages, 5 figures + Supplemental Material (2 pages, 2 figures)

References in corpus (7)

• Calorimetric Evidence for a Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in the Layered Organic Superconductor κ$-(BEDT-TTF)$_2$Cu(NCS)$_2$
• Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5
• Fermi surface reconstruction and multiple quantum phase transitions in the antiferromagnet CeRhIn${}_5$
• Hidden order and beyond: an experimental-theoretical overview of the multifaceted behavior of URu${}_2$Si${}_2$
• Field induced density wave in the heavy fermion compound CeRhIn5
• High-Field Ultrasonic Study of Quadrupole Ordering and Crystal Symmetry Breaking in CeRhIn5
• Robust Fermi-Surface Morphology of CeRhIn${}_5$ across the Putative Field-Induced Quantum Critical Point

Cited by in corpus (4)

• Origin of the 30 T transition in CeRhIn${}_5$ in tilted magnetic fields
• Magnetic structure and Kondo lattice behavior in CeVGe${}_3$: an NMR and neutron scattering study
• Exotic magnetic phase diagram and extremely robust antiferromagnetism in Ce${}_2$RhIn${}_8$
• Excess heat capacity in magnetically ordered Ce heavy fermion metals