论文标题
磁控溅射从单个目标制造的NB3SN膜的特性
Properties of Nb3Sn films fabricated by magnetron sputtering from a single target
论文作者
论文摘要
通过单个化学计量的NB3SN靶标，在蓝宝石和细晶粒NB底物上制造了超导NB3SN薄膜。研究了在800-1000°C的温度下退火24小时的结构，形态和超导特性。检查了1000°C时退火时间的影响1、12和24小时。膜特性的特征是X射线衍射，扫描电子显微镜，原子力显微镜，能量分散X射线光谱和拉曼光谱。膜的直流超导特性的特征是四点探针测量，以下是低温温度。使用7.4 GHz蓝宝石的NB腔，在6-23 K的温度范围内测量了膜的RF表面电阻。蓝宝石上沉积的NB3SN胶片的临界温度为17.21 K，当膜在800°C退火24小时时，其临界温度为17.83 k。对于在1000°C退火的薄膜，在退火时间为12小时，表面SN含量降低至〜11.3％，在退火时间为24小时，将表面含量减少到〜4.1％。电影的拉曼光谱证实了退火后的微观结构进化。在NB上播种的NB3SN膜的RF超导临界温度为16.02 K，当膜在800°C退火24小时时，它增加到17.44 K。
Superconducting Nb3Sn films were fabricated on sapphire and fine grain Nb substrates by magnetron sputtering from a single stoichiometric Nb3Sn target. The structural, morphological and superconducting properties of the films annealed for 24 h at temperatures of 800-1000 °C were investigated. The effect of the annealing time at 1000 °C was examined for 1, 12, and 24 h. The film properties were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, and Raman spectroscopy. The DC superconducting properties of the films were characterized by a four-point probe measurement down to cryogenic temperatures. The RF surface resistance of films was measured over a temperature range of 6-23 K using a 7.4 GHz sapphire-loaded Nb cavity. As-deposited Nb3Sn films on sapphire had a superconducting critical temperature of 17.21 K, which improved to 17.83 K when the film was annealed at 800 °C for 24 h. For the films annealed at 1000 °C, the surface Sn content was reduced to ~11.3 % for an annealing time of 12 h and to ~4.1 % for an annealing time of 24 h. The Raman spectra of the films confirmed the microstructural evolution after annealing. The RF superconducting critical temperature of the as-deposited Nb3Sn films on Nb was 16.02 K, which increased to 17.44 K when the film was annealed at 800 °C for 24 h.
