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arXiv · 1110.5010

Andreev nanoprobe of half-metallic CrO$_{2}$ films using superconducting cuprate tips

C. S. Turel·I. J. Guilaran·P. Xiong·J. Y. T. Wei
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Abstract

Superconducting tips of YBa$_{2} $Cu$_{3}$O$_{7-x}$ were used to perform point-contact Andreev reflection spectroscopy on half-metallic CrO$_{2}$ thin films. At 4.2K, strong suppression of the d-wave Andreev reflection characteristics was observed, consistent with the high spin polarization of CrO$_{2}$. Our technique was validated by comparison with data taken on non-magnetic Au films, and with data taken by superconducting Pb tips. The point contacts were estimated to be $\lesssim$ 10nm in size, attesting to their ballistic and microscopic nature. Our results demonstrate the feasibility of using superconducting cuprate tips as spin-sensitive nanoprobes of ferromagnets.

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C. S. Turel, I. J. Guilaran, P. Xiong, J. Y. T. Wei. 2011-10-23. Andreev nanoprobe of half-metallic CrO$_{2}$ films using superconducting cuprate tips. https://doi.org/10.1063/1.3659411

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