Microscopic analysis of the chemical reaction between Fe(Te,Se) thin films and underlying CaF${}_2$

Abstract

To understand the chemical reaction at the interface of materials, we performed a transmission electron microscopy (TEM) observation in four types of Fe(Te,Se) superconducting thin films prepared on different types of substrates: CaF2 substrate, CaF2 substrate with a CaF2 buffer layer, CaF2 substrate with a FeSe buffer layer, and a LaAlO3 substrate with a CaF2 buffer layer. Based on the energy-dispersive X-ray spectrometer (EDX) analysis, we found possible interdiffusion between fluorine and selenium that has a strong influence on the superconductivity in Fe(Te,Se) films. The chemical interdiffusion also plays a significant role in the variation of the lattice parameters. The lattice parameters of the Fe(Te,Se) thin films are primarily determined by the chemical substitution of anions, and the lattice mismatch only plays a secondary role.

30 pages, 9 figure

References in corpus (11)

• Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• The superconductivity at 18 K in LiFeAs system
• Superconductivity at 27 K in tetragonal FeSe under high pressure
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Bulk Superconductivity at 14 K in Single Crystals of Fe1+yTexSe1-x
• Superconductivity at 17 K in (Fe2P2)(Sr4Sc2O6): a new superconducting layered pnictide oxide with a thick perovskite oxide layer
• Systematic Comparison of Eight Substrates in the Growth of FeSe${}_{0.5}$Te${}_{0.5}$ Superconducting Thin Films
• Epitaxial growth of FeSe${}_{0.5}$Te${}_{0.5}$ thin films on CaF${}_2$ substrates with high critical current density
• Preparation and superconductivity of iron selenide thin films

Cited by in corpus (8)

• Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe${}_{1-x}$Te${}_x$ thin films
• Enhancement of the Superconducting Transition Temperature in FeSe Epitaxial Thin Films by Anisotropic Compression
• Highly effective and isotropic pinning in epitaxial Fe(Se,Te) thin films grown on CaF2 substrates
• Versatile fluoride substrates for Fe-based superconducting thin films
• High performance FeSe0.5Te0.5 thin films grown at low temperature by pulsed laser deposition
• Interface control by homoepitaxial growth in pulsed laser deposited iron chalcogenide thin ilms
• The influence of the in-plane lattice constant on the superconducting transition temperature of FeSe0.7Te0.3 thin films
• Stabilization and heteroepitaxial growth of metastable tetragonal FeS thin films by pulsed laser deposition