Infinite-layer fluoro-nickelates as d 9 model materials

Abstract

Abstract We study theoretically the fluoro-nickelate series ANiF2 (A = Li, Na, K, Rb, Cs) in the tetragonal P4/mmm infinite-layer structure. We use density functional theory to determine the structural parameters and the electronic band structure of these unprecedented compounds. Thus, we predict these materials as model d  9 systems where the Ni1 +  oxidation is realized and the low-energy physics is exclusively determined by the Ni-3d bands. Fluoro-nickelates of this class thus offer an ideal platform for the study of intriguing physics that emerges out of the special d  9 electronic configuration, notably high-temperature unconventional superconductivity.