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

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.

通过硝化五氧化二钒纳米颗粒（NP）和纳米线（NW）制备了VNx纳米颗粒和纳米线。五氧化二钒纳米颗粒和纳米线是通过一种简便的水热法合成的。磁化率（χ）和磁化强度测量表明，纳米线在5.8 K的温度下呈现长程超导有序（LRSO），但对于纳米颗粒样品，至少在低至2 K时没有观察到LRSO，这一温度比相应的块体材料低得多，同时纳米颗粒和纳米线至少在低至2 K时都没有长程磁有序。然而，χ数据表明，两个样品在其磁化率中都具有较高的类似泡利分量χ0（对于纳米颗粒，χ0≈2.22×10⁻⁴ emu/mol，对于纳米线，χ0≈5×10⁻⁴ emu/mol）。此外，对于纳米线样品，χ具有很强的磁场依赖性，并呈现出非线性场极化特征，表明存在强自旋 - 轨道耦合。