The current-voltage characteristics and dynamic conductance spectra of the SnS junction in Ba(Fe, Ni)₂As₂ superconducting pnictide of almost optimal composition have been obtained. A slight slope of the electronic density of states near the Fermi level has been detected. Using multiple Andreev reflection spectroscopy, we have directly determined the values and the temperature dependences of the two superconducting order parameters and estimated their anisotropy. We have shown that the obtained temperature dependences of Andreev excess current and Andreev zero-bias conductance could be fitted with a two-band model, and estimated the partial conductances of the two effective bands where the large and the small gaps are developed.

获得了几乎最佳组成的Ba（Fe，Ni）₂ As ₂超导硫化物中SnS结的电流-电压特性和动态电导谱。已经检测到费米能级附近的态的电子密度略有倾斜。我们使用多个Andreev反射光谱法直接确定了两个超导阶参数的值和温度依赖性，并估计了它们的各向异性。我们已经表明，所获得的Andreev过剩电流和Andreev零偏置电导的温度依赖性可以用两频带模型拟合，并估算出出现了大间隙和小间隙的两个有效频带的部分电导。