Magnetic and superconducting properties of spin-fluctuation-limited superconducting nanoscale VNx

Abstract

VNx nanoparticles and nanowires have been prepared by nitrifying V2O5 nanoparticles (NP) and nanowires (NW). The V2O5 NP and NW were synthesized by a facile hydrothermal method. Magnetic susceptibility (χ) and magnetization measurements showed long range superconducting ordering (LRSO) at the temperature of 5.8 K for NW, but there was no observation of LRSO (at least down to 2 K) for the NP sample, which is a much lower temperature than for the corresponding bulk, while both NP and NW showed the absence of long range magnetic ordering, at least down to 2 K. However, the χ data showed that both samples possess a high Pauli-like component, χ0, in their susceptibility (χ0 ≈ 2.22 × 10−4 emu/mol for NP and 5 × 10−4 emu/mol for NW). Moreover, for the NW samples, χ has a strong magnetic field dependence and presents a non-linear field-polarization feature, suggesting strong spin-orbit coupling.