In this study, we demonstrate the successful fabrication of ${\mathrm{TiO}}_2/\mathrm{FeSe}/{\mathrm{SrTiO}}_3$ and ${\mathrm{TiO}}_2/\mathrm{FeSe}/{\mathrm{LaAlO}}_3$ heterostructures using PLD. When the growth rates were sufficiently low, anatase ${\mathrm{TiO}}_2$, which has been reported to induce superconductivity in FeSe, could be grown epitaxially on FeSe. For ${\mathrm{TiO}}_2/\mathrm{FeSe}/{\mathrm{SrTiO}}_3$ with FeSe layers thicker than 5 nm, the $\mathrm{FeSe}/{\mathrm{TiO}}_2$ interface was clean, as confirmed by the observation of Laue fringes around the FeSe(001) reflection. Although a thinner FeSe layer is expected to enhance $T_{\mathrm{c}}$, we could not observe such behavior because it was difficult to realize interfacial superconductivity while growing anatase ${\mathrm{TiO}}_2$. Most strikingly, superconductivity appeared when ${\mathrm{TiO}}_2$ was deposited on $\mathrm{FeSe}/{\mathrm{LaAlO}}_3$, 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 platform for the exploration of interfacial superconductivity in iron-based superconductors.

Close

PrevNext

View figure in article

• Superconductivity
• Multilayer thin films
• Thin films
• Physical vapor deposition