Enhancement of transition temperature in FexSe0.5Te0.5 film via iron vacancies

Authors

J C. Zhuang, University of Wollongong
Wai K. Yeoh, University of WollongongFollow
Xiangyuan Cui, University of SydneyFollow
Jung Ho Kim, University of WollongongFollow
Dongqi Shi, University of WollongongFollow
Z X. Shi, Southeast University
S P. Ringer, University of Sydney
Xiaolin Wang, University of WollongongFollow
S X. Dou, University of WollongongFollow

RIS ID

92481

Publication Details

Zhuang, J. C., Yeoh, W. K., Cui, X. Y., Kim, J. H., Shi, D. Q., Shi, Z. X., Ringer, S. P., Wang, X. L. & Dou, S. X. (2014). Enhancement of transition temperature in FexSe0.5Te0.5 film via iron vacancies. Applied Physics Letters, 104 (26), 262601-1-262601-5.

Abstract

The effects of iron deficiency in Fe x Se0.5Te0.5 thin films (0.8 ≤ x ≤ 1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (TC ) up to 21 K was observed in the most Fe deficient film (x = 0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the Fe x Se0.5Te0.5 films. The enhancement of TC shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the charge carrier population by introducing electron charge carriers, with the Fe deficient film showing more metallic behavior than the defect-free film. Our study provides a means to enhance the superconductivity and tune the charge carriers via Fe vacancy, with no reliance on chemical doping.