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arXiv · 0805.2336

Thickness dependent magnetic anisotropy of ultrathin LCMO epitaxial thin films

Norbert M. Nemes·Mar Garcia-Hernandez·Zsolt Szatmari·Titusz Feher·Ferenc Simon·Cristina Visani·Vanessa Pena·Christian Miller·Javier Garcia-Barriocanal·Flavio Bruno·Zouhair Sefrioui·Carlos Leon·Jacobo Santamaria
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Abstract

The magnetic properties of La0.7Ca0.3MnO3 (LCMO) manganite thin films were studied with magnetometry and ferromagnetic resonance as a function of film thickness. They maintain the colossal magnetoresistance behavior with a pronounced metal-insulator transition around 150-200 K, except for the very thinnest films studied (3 nm). Nevertheless, LCMO films as thin as 3 nm remain ferromagnetic, without a decrease in saturation magnetization, indicating an absence of dead-layers, although below approx. 6 nm the films remain insulating at low temperature. Magnetization hysteresis loops reveal that the magnetic easy axes lie in the plane of the film for thicknesses in the range of 4-15 nm. Ferromagnetic resonance studies confirm that the easy axes are in-plane, and find a biaxial symmetry in-plane with two, perpendicular easy axes. The directions of the easy axes with respect to the crystallographic directions of the cubic SrTiO3 substrate differ by 45 degrees in 4 nm and 15 nm thick LCMO films.

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Norbert M. Nemes, Mar Garcia-Hernandez, Zsolt Szatmari, Titusz Feher, Ferenc Simon, Cristina Visani, Vanessa Pena, Christian Miller, Javier Garcia-Barriocanal, Flavio Bruno, Zouhair Sefrioui, Carlos Leon, Jacobo Santamaria. 2008-05-15. Thickness dependent magnetic anisotropy of ultrathin LCMO epitaxial thin films. https://doi.org/10.1109/tmag.2008.2001523

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