Intra- and inter-network interactions in magnetic oxides

Abstract

Partial substitutions of Mn by a transition metal Me in the rare-earth manganites REMexMn1-xO3 results in the simultaneous presence of Mn3+ and Mn4+, triggering double exchange ferromagnetic mechanisms. The RE sublattice has its own properties and can interact with the local field imposed by the ferromagnetic network. Its orientation differs depending on the RE nature, adopting most usually a parallel (additive) direction with respect to the (applied + local) field but, in other cases, it may align in an opposite direction, resulting in an uncompensated antiferromagnetic lattice and a reversal of the magnetic moment (spin inversion) during thermal cycling. A particular case concerns the half-substituted compound ErCo0.50Mn0.50O3 for which the magnetization loop presents two well-identified anomalies, at high field (metamagnetic or spin-flop transition) and at low field (intersection of the magnetization branches).