Physics Library, Room 223A, Physics Building
Prof. Eun-Ju Moon, University of Missouri, Kansas City, presents, "Interfacial ferromagnetism engineering by octahedral modulations in complex oxide superlattices," Sept. 6 at 4 p.m. in the Physics Building Library. Refreshments will be served beginning at 3:30 p.m.
The distortions and rotations of the corner-connected BO6 octahedra in ABO3 perovskite heterostructures play a crucial role to design and to control multifunctional properties. However, isolating the effect of the subtle octahedral interface coupling is challenging and it is difficult to identify the length scale. Here I will discuss how magnetic behavior can be tailored by structural interfacial coupling of the BO6 octahedra. In epitaxial ultrathin manganite films, different substrate-induced octahedral distortions are shown to affect the magnetic and electronic properties of the ultrathin films. Isovalent manganite superlattices will be presented in which magnetic behavior can be spatially confined by tuning the superlattice period relative to the length scale of interfacial octahedral coupling. Next, I will demonstrate a structural “delta doping” approach, non-charge-based, for controlling magnetism in ultrathin layers within superlattices. Polarized neutron reflectivity and temperature dependent magnetization measurements was used to correlate enhanced magnetization with local regions of suppressed octahedral rotations in the heterostructures. The atomic-scale modulations of the magnetism in oxide interfaces derived solely from structural effects highlights the design of local rotational gradients as routes to spatial control over novel electronic or ferroic states in oxide superlattices.