Effect of Vacuum Annealing on Superconductivity in Fe(Se,Te) Single Crystals
Effect of Vacuum Annealing on Superconductivity in Fe(Se,Te) Single Crystals
复制标题
DOI：
10.7566/jpsj.82.064710
复制
发表时间：
2013-06-01
影响因子：
1.7
通讯作者：
Maeda, Atsutaka
中科院分区：
文献类型：
--
作者：
Komiya, Seiki;Hanawa, Masafumi;Maeda, Atsutaka
本文研究了真空退火对Fe（Se，Te）单晶超导电性的影响。发现在高真空（约10（-3）Pa）下退火或在密封的真空石英管中退火都不能增强超导性。在中等真空气氛（类似于1 Pa）中，发现氧化铁层出现在样品表面上，这将从晶体中抽出过量的Fe。因此，它建议，recruitment氧有效地工作，以消除多余的铁从基体的Fe（Se，Te）晶体，从而提高超导转变温度。我们的运输测量表明，过量的铁散射电子和空穴型通道的载流子以不同的方式。我们讨论了两种类型的载流子的迁移率与超导性的关系。由于电子带和空穴带对超导电性的发生都很重要，过量的Fe会抑制超导电性，主要是由于电子的强烈散射。
The effect of vacuum annealing on superconductivity is investigated in Fe(Se, Te) single crystals. It is found that superconductivity is not enhanced by annealing under high vacuum (similar to 10(-3) Pa) or by annealing in a sealed evacuated quartz tube. In a moderate vacuum atmosphere (similar to 1 Pa), iron oxide layers are found to show up on sample surfaces, which would draw excess Fe out of the crystal. Thus, it is suggested that remanent oxygen effectively works to remove excess Fe from the matrix of Fe(Se,Te) crystals, resulting improvement of superconducting transition temperature. Our transport measurements suggest that the excess Fe scatters the carriers on electron- and hole-type channels in a different manner. We discuss how the mobility of two types of carriers correlate with superconductivity. Since both the electron and hole bands are important for the occurrence of superconductivity, excess Fe would suppress superconductivity mainly due to strong scattering of electrons.