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arXiv · 0707.4411

Intrinsic tunneling in phase separated manganites

G. Singh-Bhalla·S. Selcuk·T. Dhakal·A. Biswas·A. F. Hebard
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Abstract

We present evidence of direct electron tunneling across intrinsic insulating regions in sub-micrometer wide bridges of the phase separated ferromagnet (La,Pr,Ca)MnO$_3$. Upon cooling below the Curie temperature, a predominantly ferromagnetic supercooled state persists where tunneling across the intrinsic tunnel barriers (ITBs) results in metastable, temperature-independent, high-resistance plateaus over a large range of temperatures. Upon application of a magnetic field, our data reveal that the ITBs are extinguished resulting in sharp, colossal, low-field resistance drops. Our results compare well to theoretical predictions of magnetic domain walls coinciding with the intrinsic insulating phase.

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G. Singh-Bhalla, S. Selcuk, T. Dhakal, A. Biswas, A. F. Hebard. 2009-02-10. Intrinsic tunneling in phase separated manganites. https://arxiv.org/abs/0707.4411

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