Crossover from charge density wave stabilized antiferromagnetism to superconductivity in Nd1−xLaxNiC2 compounds

Abstract

The path from the charge density wave antiferromagnet NdNiC2 to a noncentrosymmetric superconductor LaNiC2 has been studied by gradual replacement of Nd by La ions. The evolution of physical properties has been explored by structural, magnetic, transport, magnetoresistance and specific heat measurements. With the substitution of La for Nd, the Peierls temperature is gradually suppressed, which falls within the BCS mean-field relation for chemical pressure with a critical concentration of xc = 0.38. As long as charge density wave is maintained, the antiferromagnetic ground state remains robust against doping and despite of a Nel temperature reduction shows a rapid and sharp magnetic transition. Once the CDW is completely suppressed, intermediate compounds of the Nd1−xLaxNiC2 series reveal symptoms of a gradual softening of the features associated with AFM transition and increase of the spin disorder. Immediately after the antiferromagnetic transition is depressed to zero temperature, the further incorporation of La ions results in the emergence of superconductivity. This crossover in the Nd1−xLaxNiC2 is discussed in the terms of the possible quantum critical point.

Pressure influence on the valence and magnetic state of Yb ions in noncentrosymmetric heavy-fermion YbNiC2

“…The family of NC carbides RNiC 2 (where R is a rareearth element) is studied intensively. The many nontrivial phenomena have been observed in them, such as quantum critical behavior, interplay of charge density wave (CDW), magnetism, and unconventional superconductivity [30][31][32][33][34][35][36][37][38]. The compounds with R = Nd, Tb, Dy, Ho, Er, and Tm order antiferromagnetically at low temperatures [39,40].…”