2026/07/24 by K. Madani, Q. N. Meier, A. Cano
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mtrl-sci #cond-mat.str-el
Nickelate materials exhibit rich electronic properties that can be engineered toward cuprate-like regimes through topotactic and mixed-anion chemistry. Using first-principles calculations, we investigate the newly synthesized double infinite-layer oxyfluoride La3Ni2O5F and its evolution under chemical pressure and epitaxial strain. The calculated phonon spectrum confirms the dynamical stability of the reported double infinite-layer crystal structure. Further, we find a highly two-dimensional cuprate-like Fermi surface dominated by Ni-dx2-y2 states, with a moderate rare-earth-derived self-doping yielding an effective ∼ d1.2x2-y2 filling. These electronic features remain remarkably robust under both chemical pressure and epitaxial strain. Spin-polarized calculations further reveal an extended manifold of nearly degenerate magnetic configurations with different in-plane and out-of-plane spin arrangements. Compressive strain further enhances this magnetic frustration while leaving the underlying electronic structure largely unchanged. Our results thus identify La3Ni2O5F as a promising cuprate analogue and establish lattice engineering as an effective strategy for fine tuning its electronic and magnetic properties.