Novel dynamical effects and persistent memory in phase separated manganites.
The time dependent response of the magnetic and transport properties of Fe-doped phase separated (PS) manganite La(0.5)Ca(0.5)MnO3 is reported. The nontrivial coexistence of ferromagnetic (FM) and non-FM regions induces a slow dynamics which leads to time relaxation and cooling rate dependence within the PS regime. This dynamics influences physical properties drastically. On one hand, metalliclike behavior, assumed to be a fingerprint of percolation, can be also observed before the FM phase percolates as a result of dynamical contributions. On the other hand, two novel effects for the manganites are reported, namely, the rejuvenation of the resistivity after aging and a persistent memory of low magnetic fields (<1 T), imprinted in the amount of the FM phase.
Levy
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P
Departamento de Física, Comisión Nacional de Energía Atómica, Gral Paz 1499 (1650) San Martín, Buenos Aires, Argentina.
Parisi
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F
Granja
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L
Indelicato
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E
Polla
G
G