Superconductivity in heavy-fermionCeRh2Si2

Abstract

We report the discovery of a superconducting transition in the heavy-fermion compound CeRh 2 Si 2 under hydrostatic pressure. Superconductivity appears at pressures above about 9 kbar, near the critical pressure required to suppress antiferromagnetic order ͓T N ( Pϭ0)ϭ36 K͔. Onset of superconductivity occurs at a temperature of Ϸ350 mK. Resistivity measurements as a function of field at constant temperature allow us to build an H*-T phase diagram for the onset of superconductivity. A Ginzburg-Landau analysis of the initial slope of the critical field leads to an effective mass of m*/m 0 Ϸ200, supporting the heavy-fermion nature of superconductivity in CeRh 2 Si 2 . Magnetic ac susceptibility ( ac ) shows a diamagnetic response corresponding to about 1% of perfect diamagnetism. The size of the feature in ac also is strongly peaked at a pressure of Ϸ9 kbar.

Pressure-Induced Superconductivity in Quasi-2DCeRhIn5

“…0. Interestingly, in several of these materials, heavy-fermion superconductivity appears as the zero-temperature magnetic-nonmagnetic boundary is approached by applied pressure [3][4][5][6]. These observations support the widely held view that heavy-fermion superconductivity is mediated by spin fluctuations that are present near this boundary [7].…”

“…, found in resistivity and specific heat data above 9 kbar. This phase diagram is unlike any previously reported for Ce heavy-fermion compounds [3][4][5][6] and is apparently contrary to that expected from the Doniach model. The first-order-like transition is approximately coincident with the change in sign of the pressure dependence of T max and the pressure at which T xm extrapolates to T 0.…”

Calorimetric and transport investigations ofCePd2+xGe2−xWilhelm1, Jaccard2 2002Phys. Rev. B

“…The electronic interactions in heavy-Fermion (HF) compounds can be influenced in such a way that high pressure favors the Kondo interaction in Ce-compounds [1,2,3,4,5,6,7,8,9] and the RKKY interaction in Yb-systems [10,11]. Thus, pressure suppresses (favors) long range magnetic order and enhances (weakens) the screening of the localized 4f -electrons.…”

Effect of hydrostatic pressure on the ambient pressure superconductor CePtSi

“…Since the discovery of sc in the heavy fermion compound CeCu2Si2 at atmospheric pressure [1], only a few Ce-based systems were found which also exhibit sc at atmospheric pressure, like CeMIn5 (M=Co, Ir) [4]. Most superconducting pure Ce-based systems show sc only under applied pressure sufficient to suppress long range magnetic order, like CeIn3 [2] or CeRh2Si2 [3]. CeIn3 displays a typical temperature-pressure phase diagram for these compounds; antiferromagnetism (afm) is suppressed to zero temperature with pressure and sc develops right in the vicinity where afm disappears [2].…”