Competing anisotropies and complex magnetism in SrRuO$_{3}$/SrMnO$_{3}$ superlattices
ORAL
Abstract
Using element-specific x-ray resonance techniques, we have investigated the interfacial magnetic coupling in SrRuO$_{3}$/SrMnO$_{3}$ superlattices. A strong out-of-plane SRO anisotropy coupled with AFM Ru-Mn interactions result in a canted Mn structure with a significant induced net Mn moment that reduces to zero under a strong magnetic field. At T $>$ T$_{C SRO}$, the SRO anisotropy is removed and the planar Mn AFM structure cants to produce a net Mn moment along the field direction. Below T$_{C}$, the net development of in-plane Mn moment is suppressed by partially frustrated exchange interactions at the AFM-SMO/FM-SRO interfaces and competing Mn-Ru anisotropies. Hysteretic magnetization curves show a two-step magnetization reversal and enhanced coercivity. X-ray measurements confirm that the low-field magnetization reversal coincides with ``free'' Ru moments inside the SRO layers and that the high-field magnetization reversal involves the interfacial magnetization in the SMO layers and provide strong evidence for the presence of pinned SRO moments at the SRO/SMO interface.
*Work supported by the Institute for NanoScience, Engineering and Technology - U.S. Department of Education and the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
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