Physics of the Solid State

, Volume 48, Issue 3, pp 432–440 | Cite as

Spin polarization of charge carriers and Andreev reflection in (LaCa)MnO/superconductor point contacts

  • A. I. D’yachenko
  • V. A. D’yachenko
  • V. Yu. Tarenkov
  • V. N. Krivoruchko
Metals and Superconductors

Abstract

Spin polarization of charge carriers in La0.65Ca0.35MnO3 (LCMO) is studied using point-contact Andreev spectroscopy. Pb and MgB2 are used to make superconducting electrodes. In all cases, the transport spin polarization obtained from the conductivity of LCMO/superconductor point contacts does not exceed 80–85%. Different models of the current flow through the superconductor-ferromagnetic metal contact and possible reasons for noncomplete spin polarization of a current in manganites are explored. The level of spin polarization observed in Sharvin contacts (contact area ∼104 Å2) is most naturally explained in terms of a model that suggests separation of the crystal into nanosized magnetic phases, only one of which is a ferromagnetic metal with full spin polarization of charge carriers.

PACS numbers

74.45.+c 74.50.+r 74.81.-g 

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Copyright information

© Pleiades Publishing, Inc. 2006

Authors and Affiliations

  • A. I. D’yachenko
    • 1
  • V. A. D’yachenko
    • 1
  • V. Yu. Tarenkov
    • 1
  • V. N. Krivoruchko
    • 1
  1. 1.Donetsk Physicotechnical InstituteNational Academy of Sciences of UkraineDonetskUkraine

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