Issue
EPL
Volume 83, Number 2, July 2008
Article Number 27007
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/27007
Published online 03 July 2008
EPL, 83 (2008) 27007
DOI: 10.1209/0295-5075/83/27007

Superconductivity in Sr2RuO4-Sr3Ru2O7 eutectic crystals

R. Fittipaldi1, 2, A. Vecchione1, 2, R. Ciancio1, 2, 3, S. Pace1, 2, M. Cuoco1, 2, D. Stornaiuolo4, D. Born4, F. Tafuri4, 5, E. Olsson3, S. Kittaka6, H. Yaguchi6 and Y. Maeno6

1  CNR-INFM, Laboratorio Regionale SuperMat - Baronissi (SA), Italy, EU
2  Dipartimento di Fisica "E. R. Caianiello", Università di Salerno - Baronissi (SA), Italy, EU
3  Department of Applied Physics, Chalmers University of Technology, University of Chalmers - Goteborg, Sweden, EU
4  CNR-INFM Coherentia and Dipartimento di Scienze Fisiche, Università di Napoli Federico II - Napoli, Italy, EU
5  Dipartimento Ingegneria dell'Informazione, Seconda Università di Napoli - Aversa (CE), Italy, EU
6  Department of Physics, Kyoto University - Kyoto 606-8502, Japan


received 17 March 2008; accepted in final form 4 June 2008; published July 2008
published online 3 July 2008

Abstract
Superconducting behavior has been observed in the Sr2RuO4-Sr3Ru2O7 eutectic system as grown by the flux-feeding floating-zone technique. A supercurrent flows across a single interface between Sr2RuO4 and Sr3Ru2O7 areas at distances that are far beyond those expected in a conventional proximity effect. The current-voltage characteristics within the Sr3Ru2O7 macrodomain, as extracted from the eutectic, exhibit signatures of superconductivity in the bilayered Sr3Ru2O7 region. Detailed microstructural, morphological and compositional analyses address issues on the concentration and the size of Sr2RuO4 inclusions within the Sr3Ru2O7 matrix. We speculate on the possibility of inhomogeneous superconductivity in the eutectic Sr3Ru2O7 and exotic pairing induced by the Sr2RuO4 inclusions.

PACS
74.70.Pq - Ruthenates.
74.25.Sv - Critical currents.
61.05.C- - X-ray diffraction and scattering.

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