Superparamagnetic state in La_0.7Sr_0.3MnO₃ thin films obtained by rf-sputtering.

ABSTRACT: A novel superparamagnetic state has been observed in high quality La_0.7Sr_0.3MnO₃ (LSMO) thin films directly grown by rf-sputtering on SiO_x/Si(100) substrates. The films are nanostructured without grain boundaries, constituted by locally epitaxial nanoregions grown layer-by-layer with out-of-plane (012) preferential orientation, induced by the constrain of the native silicon oxide. Low magnetic field ZFC-FC magnetization curves show a cross-over from superparamagnetic to ferromagnetic state dependent of the thickness. The thicker film (140 nm) exhibits typical ferromagnetic order. The thinner films (40 and 60 nm) exhibit superparamagnetic behavior attributed to interacting ferromagnetic monodomain nanoregions with critical size, random in-plane or

SUBMITTER: Ramirez Camacho MC 

PROVIDER: S-EPMC7018749 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature