Flexomagnetism is a prominent example of flexoeffects and shows great potential in micro/nanodevices where strain gradient could be extremely large. Herein, we demonstrate intrinsic flexomagnetic response in antiferromagnetic monolayer FeSe by applying a constant strain gradient and decipher the associated mechanism via first-principles calculations. We find that the flexomagnetic response of monolayer FeSe is linear under longitudinal, in-plane shear, out-of-plane shear, and transverse strain gradients, with an intrinsic flexomagnetic coefficient up to $3.1{\mu }_{\text{B}}\AA$. By introducing a geometrical bond-angle parameter $\mathrm{\Delta }\theta$, we identify the crystal environment difference of magnetic atoms as the origin of the strain-gradient-induced net magnetic moment, enabling a potentially unified framework to decipher the flexomagnetic mechanism in antiferromagnets. The $d_{yz}$ and $d_{z^2}$ orbitals are further found as the main contributors to flexomagnetism, serving as the direct electronic basis for the flexomagnetic effect. We also reveal that strain gradients could manipulate the spin-orbit coupling strength of $d_{xz}\text{−}{d}_{yz}$ and $d_{z^2}\text{−}{d}_{yz}$ orbitals and thus tune the magnetic anisotropy. Our findings provide a comprehensive discussion on the magnetic responses to strain gradients and their underlying mechanisms in monolayers and could inspire the future exploration of flexible magnetic applications by leveraging flexomagnetism.

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• Atomic & molecular structure
• Density functional theory
• Atoms
• Magnetic moment