LAUSR

We report the control of the inter-plane magnetic exchange coupling in CaIrO3 perovskite thin films and superlattices with SrTiO3. By analysing the anisotropic magneto-transport data, we demonstrate that a semi-metallic paramagnetic CaIrO3 turns into a canted antiferromagnetic Mott insulator at reduced dimensions. The emergence of a biaxial magneto-crystalline anisotropy indicates the canted moment responding to the cubic symmetry. Extending to superlattices and probing oxygen octahedral rotation by half-integer X-ray Braggs diffraction, a more complete picture about the canted moment evolution with inter-plane coupling can be understood. Remarkably, a rotation of the canted moments' easy axes by 45o is also observed by a sign reversal of the in-plane strain. These results demonstrate the robustness of anisotropic magnetoresistance in revealing quasi two-dimensional canted antiferromagnets, as well as valuable insights about quadrupolar magnetoelastic coupling, relevant for designing future antiferromagnetic spintronic devices.