Strain-mediated control of orbital ordering planes in heteroepitaxial lanthanum manganite thin films

Strain engineering which controls the misfit strain of heteroepitaxial thin films leads to distinctive physical properties in contrast to the intrinsic properties of unstrained bulk materials Perovskite LaMnO$_{\mathrm{3}}$ (LMO) has attracted considerable attention due to strong coupling among the lattice, charge, spin and orbital degrees of freedom. Bulk LMO is known to be an A-type antiferromagnetic (T$_{N}$\textasciitilde 140 K) Mott insulator, and its orbital ordering plane is established due to cooperative Jahn-Teller distortion below \textasciitilde 750 K. Previous studies have focused on the orbital ordering planes of the bulk LMO but not researched on correlation between orbital planes and misfit stain. To figure out the strain dependence of orbital ordering planes, we have grown LMO thin films on four different substrates, $i.e.$, DyScO$_{\mathrm{3}}$(110), GaScO$_{\mathrm{3}}$(110), SrTiO$_{\mathrm{3}}$(001), and LSAT(001), using the pulsed laser deposition technique. The films have been characterized by atomic force microscopy and x-ray diffraction. We have performed resonant x-ray scattering to identify orbital ordering plane on each film. We have found that orbital ordering planes can be modulated depending on the misfit strain.