Novel dynamical effects in phase separated manganites

LEVY, PABLO; FRANCISCO PARISI,; GRANJA, LETICIA; INDELICATO, EVANGELINA; GRISELDA POLLA,; P. LEVY

Phys. Rev. Lett.

The American Physical Society

Año: 2002 vol. 89 p. 13700 - 13700

The time dependent response of the magnetic and transport properties of Fe-doped phase separated(PS) manganite La 0 :5 Ca 0 :5 MnO 3 is reported. The nontrivial coexistence of ferromagnetic (FM) and non-FMregions induces a slow dynamics which leads to time relaxation and cooling rate dependence withinthe PS regime. This dynamics influences physical properties drastically. On one hand, metalliclikebehavior, assumed to be a fingerprint of percolation, can be also observed before the FM phasepercolates as a result of dynamical contributions. On the other hand, two novel effects for themanganites are reported, namely, the rejuvenation of the resistivity after aging and a persistent memoryof low magnetic fields ( <1T ), imprinted in the amount of the FM phase.