Orbital ordering and enhanced magnetic frustration of strained

Epitaxial thin films of multiferroic perovskite $\chem{BiMnO_3}$ were synthesized on $\chem{SrTiO_3}$ substrates, and orbital ordering and magnetic properties of the thin films were investigated. The ordering of the $\chem{Mn^{3+}}$ eg orbitals at a wave vector $(\frac{1}{4}\frac{1}{4}\frac{1}{4})$ was detected by Mn K-edge resonant X-ray scattering. This peculiar orbital order inherently contains magnetic frustration. While bulk $\chem{BiMnO_3}$ is known to exhibit simple ferromagnetism, the frustration enhanced by in-plane compressive strains in the films brings about cluster-glass-like properties