Enhancement of Transition Temperature in FexSe0.5Te0.5 Film via Iron Vacancies

Abstract

The effects of iron deficiency in FexSe0.5Te0.5 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 21K 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 FexSe0.5Te0.5 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.

15 pages, 4 figures

References in corpus (8)

• Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
• Bulk Superconductivity at 14 K in Single Crystals of Fe1+yTexSe1-x
• Systematic Comparison of Eight Substrates in the Growth of FeSe${}_{0.5}$Te${}_{0.5}$ Superconducting Thin Films
• Effective doping and suppression of Fermi surface reconstruction via Fe vacancy disorder in KxFe2-ySe2

Cited by in corpus (5)

• Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe${}_{1-x}$Te${}_x$ thin films
• Unabridged phase diagram for single-phased FeSexTe1-x thin films
• Influence of interstitial Fe to the phase diagram of Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$ single crystals
• High performance FeSe0.5Te0.5 thin films grown at low temperature by pulsed laser deposition
• Influence of substrate type on transport properties of superconducting FeSe0.5Te0.5 thin films