Impact of isoelectronic substitution and hydrostatic pressure on the quantum critical properties of CeRhSi3

J Valenta; T Naka; M Diviš; M Vališka; P Proschek; K Vlášková; M Klicpera; J Prokleška; J Custers; J Prchal

doi:10.1088/1361-648X/aba015

Impact of isoelectronic substitution and hydrostatic pressure on the quantum critical properties of CeRhSi₃

J Phys Condens Matter. 2020 Jul 23;32(42). doi: 10.1088/1361-648X/aba015.

Authors

J Valenta¹, T Naka², M Diviš¹, M Vališka¹, P Proschek¹, K Vlášková¹, M Klicpera¹, J Prokleška¹, J Custers¹, J Prchal¹

Affiliations

¹ Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
² National Institute for Materials Science, Research Center for Functional Materials, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.

PMID: 32585641
DOI: 10.1088/1361-648X/aba015

Abstract

There is an ongoing dispute in the community about the absence of a magnetic quantum critical point (QCP) in the noncentrosymmetric heavy fermion compound CeRhSi₃. In order to explore this question we prepared single crystals of CeRh(Si_1-xGe_x)₃withx= 0.05 and 0.15 and determined the temperature-pressure (T-p) phase diagram by means of measurements of the electrical resistivity. The substitution of isoelectronic but large Ge enforces a lattice volume increase resulting in a weakening of the Kondo interaction. As a result, thex= 0.05 andx= 0.15 compound exhibit a transition into the antiferromagnetic (AFM) at higher temperatures beingT_N= 4.7 K andT_N1= 19.7 K, respectively. Application of pressure suppressesT_N(T_N1) monotonically and pressure induced superconductivity is observed in both Ge-substituted compounds abovep⩾ 2.16 GPa (x= 0.05) andp⩾ 2.93 GPa (x= 0.15). Extrapolation ofT_N(p) → 0 of CeRh(Si_0.95Ge_0.05)₃yields a critical pressure ofp_c≈ 3.4 GPa (in CeRh(Si_0.85Ge_0.15)₃ p_c≈ 3.5 GPa) pointing to the presence of an AFM QCP located deep inside the superconducting state.

Keywords: heavy fermion; magnetic transitions; quantum critical phenomena; superconductivity.