Magnetic interactions and anisotropies present in ferromagnetic nanotubes of manganites.

R. D. SANCHEZ; J. CURIALE; H. E. TROIANI; A. BUTERA; A. G. LEYVA; P. LEVY

Berlin Alemania

Conferencia; Berlin 08, DPG Conference; 2008

DPG

We present results about FM manganites with tubular morphology at the nanoscale. Although, their FM transition temperatures (Tc) are close to the bulk, the rest of their magnetic properties are notably affected. The external diameters is 800nm. The walls are constituted by an assembly of nanoparticles (25nm). The wall thicknesses are 45 nm for LSMO and 60 nm for LCMO. Our previous study[1] shows that each grain is a single magnetic domain, with a thick dead layer on the surface and dipolar magnetic interactions between them. In order to characterize  completely the interactions between the magnetic nanograins, we present a study of First-Order Reversal Curves (FORC) diagrams. We discuss the role of the interaction in the configuration of the magnetic moments in these nanostructures. We complete this study with the results of FMR technique on aligned LSMO nanotubes about the magnetic anisotropies present in the  nanotubes. [1] J. Curiale,et al. Phys. Rev. B 75, 224410 (2007) RDS acknowledges financial support of DFG (via its Leibniz-Program) during his stay in G¨ottingen.