摘要
Monocrystal Sn nanorods encapsulated in the multi-walled carbon nanotubes(Sn@CNT NRs), were fabricated by a facile arc-discharge plasma process, using bulk Sn as the raw target and methane as the gaseous carbon source. The typical Sn@CNT NRs are 40–90 nm in diameter and400–500 nm in length. The CNTs protect the inner Sn nanorods from oxidation. Temperature dependent I–V curve and electronic resistance reveal that the dielectric behavior of Sn@CNT NRs is attributed to the multi-wall CNTs shell and follows Mott-David variable range hopping [ln R(T)∝T-1/4]model above the superconducting critical temperature of3.69 K, with semiconductor–superconductor transition(SST).Josephson junction of Sn/CNT/Sn layered structure is responsible for the superconducting behavior of Sn@CNT NRs.
通过简易的电弧放电等离子法,用块体锡作为原料靶材、甲烷作为气态碳源组装了多壁碳纳米管封装单晶锡纳米棒(Sn@CNT NRs). Sn@CNT NRs直径为40–90 nm,长为400–500 nm.碳纳米管保护了内部的锡纳米棒免于氧化,并且构建了一种结合良好的纳米复合材料.温度相关的I-V曲线及电阻率的测量显示,在超导临界温度3.69 K之上Sn@CNT NRs的介电行为归因于碳纳米管壳,且按照莫特-戴维变程跳跃(ln R(T)∝T^(-1/4))模式,半导体-超导体的转变(SST)是Sn@CNT纳米棒的一个显著特征.此外,发现Sn@CNT NRs的超导行为是由锡/碳纳米管/锡的层结构形成的约瑟夫森结导致的.
基金
financially supported by the National Natural Science Foundation of China(51331006 and 51271044)
