Electron-tunneling studies of thin films of high-Tc superconducting La-Sr-Cu-O

M. Naito; D. P. E. Smith; M. D. Kirk; B. Oh; M. R. Hahn; K. Char; D. B. Mitzi; J. Z. Sun; D. J. Webb; M. R. Beasley; O. Fischer; T. H. Geballe; R. H. Hammond; A. Kapitulnik; C. F. Quate

doi:10.1103/PhysRevB.35.7228

Electron-tunneling studies of thin films of high-Tc superconducting La-Sr-Cu-O

M. Naito, D. P. E. Smith, M. D. Kirk, B. Oh, M. R. Hahn, K. Char, D. B. Mitzi, J. Z. Sun, D. J. Webb, M. R. Beasley, O. Fischer, T. H. Geballe, R. H. Hammond, A. Kapitulnik, C. F. Quate

DOI 10.1103/PhysRevB.35.7228 · Physical Review B

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Abstract

We report results of the study of electron tunneling into thin films of the new high-Tc superconductor La-Sr-Cu-O. Both sandwich-type tunneling with a Pb counterelectrode and point-contact tunneling have been successfully achieved. The results show exceptionally large energy gaps in these materials (roughly 20, 30, and possibly even 60 mV), larger than previously obtained on bulk sintered powders. We interpret these results as due to large anisotropy in this material or due to the presence of a a very high-Tc layer near the surface of the films. The method of preparation of this new superconductor in thin film form is also discussed.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
(La1-xSrx)2CuO4-y Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	30	Pressure not reported	onset
(La1-xSrx)2CuO4-y Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	15	Pressure not reported	zero_resistance