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在普通高真空(～1×10~(-5)乇)的条件下用电子来蒸发制作出了高质量的Nb超导薄膜,超导转变温度Tc可以达到9.25K,接近大块(?)Vb的Tc值(～9.26K)。通过实验确定了Vb膜的Tc与室温和液氮温度电阻比β之间的对应关系,因此提出了用Nb膜的β值来估计Tc的简便方法。 研究了不同蒸发条件(Nb膜厚度、蒸发速率、真空度、衬底温度以及衬底材料等)对Nb膜的β或Tc的影响,从而确定了较好的制作Nb膜的条件。χ射线衍射,表面分析等结果说明,在这种条件下制作的Nb膜具有较高的纯度。电子束蒸发的Nb膜已成功地应用于制作Nb超导微桥、Nb隧道结以及Nb超导传输线等方面。
High-quality Nb superconducting films were produced by electron evaporation under normal high vacuum (~1 × 10 -5 Torr). The superconducting transition temperature (Tc) can reach 9.25 K, close to the bulk The Tc value of Vb (~ 9.26K). The corresponding relationship between the Tc of Vb film and the temperature resistance ratio β between the room temperature and the liquid nitrogen was experimentally determined. Therefore, a simple and convenient method for estimating Tc by using the β value of the Nb film was proposed. The effects of different evaporation conditions (Nb film thickness, evaporation rate, vacuum degree, substrate temperature and substrate material) on the β or Tc of Nb films were investigated, and the better conditions of Nb films were determined. X-ray diffraction, surface analysis and other results show that under these conditions Nb film has a higher purity. Electron beam evaporation of Nb film has been successfully used in the manufacture of Nb superconducting micro-bridge, Nb tunnel junction and Nb superconducting transmission lines and so on.