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Giant 1/f Noise in Low-Tc CMR Manganites: Evidence of the Percolation Threshold

Published online by Cambridge University Press:  10 February 2011

V. Podzorov
Affiliation:
Serin Physics Laboratory, Rutgers University, Piscataway, NJ 08854-8019
M. Uehara
Affiliation:
Serin Physics Laboratory, Rutgers University, Piscataway, NJ 08854-8019
M. E. Gershenson
Affiliation:
Serin Physics Laboratory, Rutgers University, Piscataway, NJ 08854-8019
T. Y. Koo
Affiliation:
Bell Labs, Lucent Technologies, Murray Hill, NJ 07974
S-W. Cheong
Affiliation:
Serin Physics Laboratory, Rutgers University, Piscataway, NJ 08854-8019 Bell Labs, Lucent Technologies, Murray Hill, NJ 07974
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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 La5/8−y. Pry, Ca3/8MnO3 (y = 0.35 – 0.4) and Pr1−xCaxMnO3 (x = 0.35 – 0.5). 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. It is shown that the scale of phase separation in polycrystalline samples is much smaller than that in single crystals.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

[1] Imada, M., Fujimori, A., and Tokura, Y., Rev. Mod. Phys. 70, 1039 (1998).Google Scholar
[2] Uehara, M., Kim, K. H., and Cheong, S-W., unpublished.Google Scholar
[3] Helmholt, R. M. von et al. , Phys. Rev. Lett. 71, 2331 (1993).Google Scholar
[4] Jin, S. et al. , Science 264, 413 (1994).Google Scholar
[5] Nagaev, E. L., Sov. Phys.-Uspekhi, 39, 781 (1996).Google Scholar
[6] Cheong, S-W. and Hwang, H. Y., in Colossal Magnetoresistance Oxides, edited by Tokura, Y. (Gordon & Breach, London, 1999), ch. 7.Google Scholar
[7] Babushkina, N. A. et al. , Phys. Rev. B 59, 6994 (1999).Google Scholar
[8] Uehara, M., Mori, S., Chen, C. H., and Cheong, S-W., Nature (London) 399, 560 (1999).Google Scholar
[9] Millis, A. J., Littlewood, P. B., and Shraiman, B. I., Phys. Rev. Lett. 74, 5144 (1995).Google Scholar
[10] Röder, H., Zang, Jun, and Bishop, A. R., Phys. Rev. Lett. 76, 1356 (1996).Google Scholar
[11] Zhou, J.-S. and Goodenough, J. B., Phys. Rev. Lett. 80, 2665 (1998).Google Scholar
[12] Teresa, J. M. De et al. , Nature 386, 256 (1997).Google Scholar
[13] Rammal, R. et al. , Phys. Rev. Lett. 54, 1718 (1985).Google Scholar
[14] Kogan, Sh., Electronic Noise and Fluctuations in Solids, Cambridge University Press 1998.Google Scholar
[15] Tremblay, A.-M. S., Feng, S., and Breton, P., Phys. Rev. B. 33, 2077 (1986).Google Scholar
[16] Merithew, R. D., Weissman, M. B., O'Donnel, J., and Eckstein, J. “Mesoscopic Fluctuations in Collosal Magnetoresistance”, preprint, 1999.Google Scholar
[17] Rudman, D. A., Calabrese, J. J., and Garland, J. J., Phys. Rev. B 33, 1456 (1986).Google Scholar
[18] Chen, C. C. and Chou, Y. C., Phys. Rev. Lett. 54, 2529 (1985).Google Scholar
[19] The Pr concentration for the single crystal, estimated from the Tc ,(y) dependence, was close to 0.35 (the nominal concentration was y = 0.42).Google Scholar