Effects of Sr-doping on the electronic and spin-state properties of infinite-layer nickelates
Abstract
The recent discovery of high-Tc superconductivity (HTS) in Sr-doped NdNiO2 has sparked a renewed interest in investigating nickelates as cuprate counterparts. Parent cuprates [Cu2+: d9] are antiferromagnetic charge-transfer insulators with the involvement of a single dx2-y2 band around the Fermi level and strong p-d hybridization. In contrast, isoelectronic NdNiO2 [Ni+: d9] is metallic with a dx2-y2 band self-doped by Nd-d states. Using first-principles calculations, we study the effect of Sr-doping in the electronic and magnetic properties of infinite-layer nickelates as well as the nature of the holes. We find that hole doping tends to make the material more cuprate-like as it minimizes the self-doping effect, it enhances the p-d hybridization, and it produces low-spin (S=0, non-magnetic) Ni2+ dopants in analogy with the S=0 Zhang-Rice singlets that appear in cuprates.