Intrinsic magnetism in superconducting infinite-layer nickelates

Abstract

The discovery of superconductivity in Nd0.8Ar0.2NiO2 (ref. (1)) introduced a new family of layered nickelate superconductors that has now been extended to include a range of strontium doping(2,3), praseodymium or lanthanum in place of neodymium(4-7), and the five-layer compound Nd6Ni5O12 (ref. (8)). A number of studies have indicated that electron correlations are strong in these materials(9-15), a feature that often leads to the emergence of magnetism. Here we report muon spin rotation/relaxation studies of a series of superconducting infinite-layer nickelates. Regardless of the rare earth ion or doping, we observe an intrinsic magnetic ground state arising from local moments on the nickel sublattice. The coexistence of magnetism-which is likely to be antiferromagnetic and short-range ordered-with superconductivity is reminiscent of some iron pnictides(16) and heavy fermion compounds(17), and qualitatively distinct from the doped cuprates(18).