Phase diagram of the NdFe<inf>1-x</inf>Rh<inf>x</inf>Aso superconductor

Abstract

Polycrystalline samples with a nominal composition of NdFe 1-x Rh x AsO (0 ≤ x ≤ 0.25) were synthesized using a solid state reaction method. Bulk superconductivity with a maximum T C = 13 K is observed in the x = 0.1 sample. A temperature-composition phase diagram is established for the NdFe 1-x Rh x AsO system based on the electrical resistivity and magnetization measurements. A first-order-like transition from an antiferromagnetic state to the superconducting state at a critical Rh-doping point x C ≈ 0.045 is observed in the present phase diagram. The value for the upper critical field μ 0 H c2 (0) is estimated to be about 26 T for the x = 0.10 sample by using the Werthamer-Helfand-Hohenberg theory. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.