Valenta J, Naka T, Diviš M, Vališka M, Proschek P, Vlášková K, Klicpera M, Prokleška J, Custers J, Prchal J
Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
National Institute for Materials Science, Research Center for Functional Materials, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
J Phys Condens Matter. 2020 Jul 23;32(42). doi: 10.1088/1361-648X/aba015.
There is an ongoing dispute in the community about the absence of a magnetic quantum critical point (QCP) in the noncentrosymmetric heavy fermion compound CeRhSi. In order to explore this question we prepared single crystals of CeRh(SiGe)with= 0.05 and 0.15 and determined the temperature-pressure (-) 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, the= 0.05 and= 0.15 compound exhibit a transition into the antiferromagnetic (AFM) at higher temperatures being= 4.7 K and= 19.7 K, respectively. Application of pressure suppresses() monotonically and pressure induced superconductivity is observed in both Ge-substituted compounds above⩾ 2.16 GPa (= 0.05) and⩾ 2.93 GPa (= 0.15). Extrapolation of() → 0 of CeRh(SiGe)yields a critical pressure of≈ 3.4 GPa (in CeRh(SiGe) ≈ 3.5 GPa) pointing to the presence of an AFM QCP located deep inside the superconducting state.
