Fabrication of oxide/FeSe multilayer films using the PLD technique

Abstract

In this study, we demonstrate the successful fabrication of TiO2/FeSe/STO and TiO2/FeSe/LaAlO3 heterostructures using PLD. When the growth rates were sufficiently low, anatase TiO2, which has been reported to induce superconductivity in FeSe, could be grown epitaxially on FeSe. For TiO2/FeSe/STO, the FeSe/TiO2 interface was relatively clean, as confirmed by the observation of Laue fringes in FeSe(001) reflection. Although a thinner FeSe layer is expected to enhance Tc, our results instead suggest that deposition of TiO2 introduces additional disorder in FeSe. Most strikingly, superconductivity appeared when TiO2 was deposited on FeSe/LaAlO3, clearly demonstrating that the interaction between the top oxide layer and underlying FeSe can induce superconductivity. This work demonstrates the feasibility of fabricating FeSe/oxide superlattices by PLD, establishing a novel platform for the exploration of interfacial superconductivity in iron-based superconductors.

14 pages, 3 figures

References in corpus (11)

• Superconductivity at 27 K in tetragonal FeSe under high pressure
• Understanding and controlling the work function of perovskite oxides using Density Functional Theory
• Universal Substrate Effect on the Superconductivity of FeSe Monolayer Films
• Origin of charge transfer and enhanced electron-phonon coupling in single unit-cell FeSe films on SrTiO3
• Incoherent Cooper pairing and pseudogap behavior in single-layer FeSe/SrTiO${}_3$
• Strain-tuning of nematicity and superconductivity in single crystals of FeSe
• Enhancement of superconducting transition temperature in electrochemically etched FeSe/LaAlO${}_3$ films
• Control of band structure of FeSe single crystals via biaxial strain
• Interface superconductivity in FeSe thin films on SrTiO${}_3$grown by the PLD technique
• Positive and negative chemical pressure effects investigated in electron-doped FeSe films with an electric-double-layer structure
• Anisotropy of upper critical fields and interface superconductivity in FeSe/SrTiO3 grown by PLD