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arXiv · 1207.3826

Pressure effects on the superconducting thin film Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$

Eunsung Park·Nam Hoon Lee·Won Nam Kang·Tuson Park
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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 ($n=d\text{ln}Δρ/d\text{ln}T$) shows a funnel shape around the optimal pressure, suggesting that fluctuations associated with the anomalous normal state are responsible for high-temperature superconductivity.

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Eunsung Park, Nam Hoon Lee, Won Nam Kang, Tuson Park. 2012-07-16. Pressure effects on the superconducting thin film Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$. https://doi.org/10.1063/1.4738783

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