Pressure effects on the superconducting thin film Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$

Abstract

We report electrical resistivity measurements on a high-quality Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ thin film ($x=0.4$) under pressure. The superconducting transition temperature (=39.95 K) of the optimally-doped thin film shows a dome shape with pressure, reaching a maximal value 40.8 K at 11.8 kbar. The unusually high superconducting transition temperature and its anomalous pressure dependence are ascribed to a lattice mismatch between the LaAlO${}_3$ substrate and the thin film. The local temperature exponent of the resistivity ($n=d\text{ln}\Delta \rho /d\text{ln}T$) shows a funnel shape around the optimal pressure, suggesting that fluctuations associated with the anomalous normal state are responsible for high-temperature superconductivity.

arXiv commentTo appear in Appl. Phys. Lett

References in corpus (16)

• Superconductivity in Iron Compounds
• Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
• Superconductivity and Crystal Structures of (Ba1-xKx)Fe2As2 (x = 0 - 1)
• Similarities between structural distortions under pressure and chemical doping in superconducting BaFe2As2
• Tc=21K in epitaxial FeSe0.5Te0.5 thin films with biaxial compressive strain
• Template engineering of Co-doped BaFe2As2 single-crystal thin films
• Weak-link behavior of grain boundaries in superconducting Ba(Fe1-xCox)2As2 bicrystals
• Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
• Strong Tc dependence for strained, epitaxial Ba(Fe1-xCox)2As2 thin films
• High Critical Current Density 4 MA/cm2 in Co-Doped BaFe2As2 Epitaxial Films Grown on (La, Sr)(Al, Ta)O3 Substrates without Buffer Layers
• Effect of pressure on the structural phase transition and superconductivity in (B$_{1-x}K_x)Fe_2As_2 (x = 0 and 0.45) and SrFe_2As_2 single crystals
• Transport properties and asymmetric scattering in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ single crystals compared to the electron doped counterparts Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$}
• Thin Film Growth and Device Fabrication of Iron-Based Superconductors
• Influenced of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers
• Potassium-doped BaFe2As2 superconducting thin films with a transition temperature of 40 K
• Anion height as a controlling parameter for the superconductivity in iron pnictides and cuprates

Cited by in corpus (5)

• Strong enhancement of critical current density in both low & high fields and flux pinning mechanism under hydrostatic pressure in optimally doped (Ba,K)Fe2As2 single crystals
• Unusual pressure effects on the superconductivity of indirectly electron-doped (Ba1-xLax)Fe2As2 epitaxial films
• The malleability of uranium: manipulating the charge-density wave in epitaxial films
• Multigap superconductivity and interaction driven resonances in superconducting nanofilms with an inner potential barrier
• Correlation between non-Fermi-liquid behavior and superconductivity in (Ca, La)(Fe,Co)As2 iron arsenides: A high-pressure study