Magnetic anisotropy and planar topological Hall effect in SrMn x Ir 1- x O 3 films

Strong Coulomb repulsion and spin-orbit coupling are known to give rise to exotic physical phenomena in transition metal oxides. Here, we report magnetic and transport characteristics of (001) oriented epitaxial SrMn Ir O thin films, having both 3 and 5 elements on the perovskite sites. With the increase of Mn concentration, perpendicular magnetic anisotropy (PMA) decreases gradually in accompany with the magnetic easy axis tilting away from the out-of-plane [001] direction. X-ray absorption spectroscopy reveals that Mn electrons preferentially occupy thed3z2-r2orbital, which produces the observed PMA in the framework of spin-orbital coupling. A planar topological Hall effect appears in SrMn Ir O films with about 0.30 when the magnetic field is applied along the current, which is a result of the noncoplanar spin structure due to the competition among the PMA, the magnetic exchange interaction and the Zeeman energy. These results provide an example to show the subtle balance among complex competitions in materials with both strong correlation and spin-orbit coupling.