Anomalous exchange coupling in transition-metal-oxide based superlattices with antiferromagnetic spacer layers

Abstract

A direct correlation is seen between the coercive field (H C ) and the magnetic-fielddependent resistivity (MR) in SrMnO 3 /SrRuO 3 superlattices of perpendicular magnetic anisotropy. The magnetoresistance shows a sharp jump at H c for in-plane current and the out-of-plane magnetic field. Both H C and high-field MR also oscillate with the thickness of the SrMnO 3 spacer layers separating the metallic ruthenate. Since the spacer in these superlattices has no mobile carriers to facilitate an oscillatory coupling, we attribute the observed behavior to the spin-polarized quantum tunneling of electrons between the ferromagnetic layers and antiferromagnetically ordered t 2g spins of SrMnO 3 . 1 prellier@ensicaen.fr

Observation of Exchange Anisotropy in Single-Phase Layer-Structured Oxides with Long Periods

“…Recently, observation of the EB effect has been extended into a few quite new artificial multiferroic heterostructures910, e.g. BiFeO 3 /CoFe11 and SrMnO 3 /SrRuO 3 12. In such materials, the EB effect could be controlled by an electric field applied to the multiferroic phases on account of the effective magnetoelectric (ME) coupling.…”