The electronic and magnetic properties of tetravalent-ion-doped La0.85Zr0.15MnO3 (LZMO) thin films that were epitaxially grown on SrTiO3 (STO) and MgO substrates were studied using temperature-dependent x-ray diffraction (XRD), x-ray absorption near-edge structure, x-ray linear dichroism, and x-ray magnetic circular dichroism at the Mn L 3,2- and K-edge. XRD studies reveal that the LZMO thin films have compressive and tensile strains (along the c -axis) on the STO and MgO substrates, respectively. As the temperature is reduced from room temperature to below magnetic transition temperature, the preferentially occupied Mn majority-spin e g orbital changes from the in-plane dx 2 -y 2 to the out-of-plane d 3 z 2 -r 2 orbital for LZMO/STO, and vice versa for LZMO/MgO. Experimental results suggest that the new hopping path that is mediated by the Mn2+ ions triggers a stronger d 3 z 2 -r 2 orbital ordering of Mn3+ ions and enhances the ferromagnetic coupling between the Mn spin moments of t 2g electrons in LZMO/STO, whereas the strong tensile strain stabilizes the dx 2 -y 2 orbital by inducing lattice distortions of the MnO6 octahedra in LZMO/MgO.
