Magnetic Anisotropy of a Quasi Two-Dimensional Canted Antiferromagnet.

Lim, Zhi Shiuh; Li, Changjian; Chi, Xiao; Omar, Ganesh Ji; Ma, Haijiao Harsan; Huang, Zhen; Zeng, Shengwei; Yang, Ping et al. · Nano Lett · 2020

basic_science · Level V

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Abstract

We report the control of the interplane magnetic exchange coupling in CaIrO<sub>3</sub> perovskite thin films and superlattices with SrTiO<sub>3</sub>. By analyzing the anisotropic magneto-transport data, we demonstrate that a semimetallic paramagnetic CaIrO<sub>3</sub> 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 interplane coupling can be understood. Remarkably, a rotation of the canted moments' easy axes by 45° 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.