INVESTIGADORES
STEREN Laura beatriz
artículos
Título:
Correlation between structure and magnetic properties of manganite-based multilayers
Autor/es:
N. HABERKORN; M. SIRENA; M.GRANADA; L.B. STEREN; J. GUIMPEL
Revista:
JOURNAL OF APPLIED PHYSICS
Editorial:
AMER INST PHYSICS
Referencias:
Año: 2003 vol. 93 p. 7244 - 7246
ISSN:
0021-8979
Resumen:
We have studied the structure, magnetic, and transport properties of manganite-based multilayers A/Bi, with A=La0.55Sr0.45MnO3 (metallic ferromagnet), and spacers (Bi) of different nature: B1=SrTiO3 (nonmagnetic insulator), B2=La0.9Sr0.1MnO3 (insulator ferromagnet), and B3=La0.67Ca0.33MnO3
(paramagnetic-insulator/ferromagnet-metal). The samples are strongly
textured in the direction perpendicular to the sample surface, and
present a good interface quality with small roughness and
interdiffusion. We have found that in the A/B1/A
trilayers, the ferromagnetic electrodes are ferromagnetically coupled
for thin spacer layers and becomes decoupled for spacer thickness larger
than 3 nm. Instead, the others multilayers are ferromagnetic for all
spacer thicknesses and temperature range. This result was expected for
temperatures well below the spacer Curie temperature. We attributed the
ferromagnetic behavior of the system, found for temperatures above the
ordering temperature of the spacer, to direct exchange coupling through
short-range ordered zones in spacer layer. As expected from
magnetization results, in fact, no extrinsic magnetoresistance was
measured in these systems in the temperature range between 4.2 and 300 K