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Giant Peak of the 1/f Noise at the Metal-Insulator Transitions in Low-Tc CMR Manganites: Evidence of the Percolation Threshold at Tc

V. Podzorov·M. Uehara·M. E. Gershenson·S-W. Cheong
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Abstract

We observed a dramatic peak in the 1/f noise at the metal-insulator transition (MIT) in low-Tc manganites. This many-orders-of-magnitude noise enhancement is observed for both polycrystalline and single-crystal samples of La{5/8-y}Pr{y}Ca{3/8}MnO{3} (y=0.35-0.4) in zero magnetic field and Pr{1-x}Ca{x}MnO{3} (x=0.35-0.5) in magnetic field. This observation strongly suggests that the microscopic phase separation in the low-Tc manganites causes formation of a percolation network, and that the observed MIT is a percolation threshold.

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V. Podzorov, M. Uehara, M. E. Gershenson, S-W. Cheong. 1999-12-04. Giant Peak of the 1/f Noise at the Metal-Insulator Transitions in Low-Tc CMR Manganites: Evidence of the Percolation Threshold at Tc. https://arxiv.org/abs/cond-mat/9912064

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