Current oscillation and low-field colossal magnetoresistance effect in phase-separated manganites.
Phys Rev Lett
; 94(15): 157203, 2005 Apr 22.
Article
em En
| MEDLINE
| ID: mdl-15904181
ABSTRACT
Current-induced switching from a metallic to an insulating state is observed in phase-separated states of (La(1-y)Pr(y))0.7Ca0.3MnO3 (y=0.7) and Nd(0.5)Ca(0.5)Mn(1-z)Cr(z)O3 (z=0.03) crystals. The application of magnetic fields to this current-induced insulating state causes a pronounced low-field negative magnetoresistance effect [rho(H)/rho(0)=10(-3) at H=1 kOe]. The application of a constant voltage also causes the breakdown of the Ohmic relation above a threshold voltage. At voltages higher than this threshold value, oscillations in currents are observed. This oscillation is well reproduced by a simple model of local switching of a percolative conduction path.
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MEDLINE
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En
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Phys Rev Lett
Ano de publicação:
2005
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Article
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Japão