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Superconducting properties of nanocrystalline MgB$_2$ thin films made by an in situ annealing process

X. H. Zeng·A. Sukiasyan·X. X. Xi·Y. F. Hu·E. Wertz·Qi Li·W. Tian·H. P. Sun·X. Q. Pan·J. Lettieri·D. G. Schlom·C. O. Brubaker·Zi-Kui Liu·Qiang Li
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Abstract

We have studied the structural and superconducting properties of MgB$_2$ thin films made by pulsed laser deposition followed by in situ annealing. The cross-sectional transmission electron microscopy reveals a nanocrystalline mixture of textured MgO and MgB$_2$ with very small grain sizes. A zero-resistance transition temperature ($T_{c0}$) of 34 K and a zero-field critical current density ($J_c$) of $1.3 \times 10^6$ A/cm$^2$ were obtained. The irreversibility field was $\sim$ 8 T at low temperatures, although severe pinning instability was observed. These bulk-like superconducting properties show that the in situ deposition process can be a viable candidate for MgB$_2$ Josephson junction technologies.

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X. H. Zeng, A. Sukiasyan, X. X. Xi, Y. F. Hu, E. Wertz, Qi Li, W. Tian, H. P. Sun, X. Q. Pan, J. Lettieri, D. G. Schlom, C. O. Brubaker, Zi-Kui Liu, Qiang Li. 2001-05-03. Superconducting properties of nanocrystalline MgB$_2$ thin films made by an in situ annealing process. https://doi.org/10.1063/1.1405431

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