Layer-dependent magnetic property in a superconducting quintuple-layer nickelate La6Ni5O12

TL;DR

This study uses first-principles calculations to explore the layer-dependent magnetic properties of a superconducting nickelate, revealing how intrinsic doping and layer position influence magnetic interactions.

Contribution

It provides the first detailed analysis of magnetic interactions in La6Ni5O12, highlighting layer-dependent magnetic coupling and the effects of intrinsic hole doping.

Findings

Magnetic couplings are reduced by intrinsic hole doping.

Layer dependence significantly affects magnetic interactions.

Long-range and out-of-plane magnetic interactions are characterized.

Abstract

To investigate the detailed magnetic properties of a recently discovered superconducting nickelate Nd6Ni5O12, we performed the first-principles electronic structure calculation based on density functional theory. The band dispersion, electronic charge distribution and the magnetic moment are computed with La substituted for Nd, and compared with another structural type of nickel-based superconducting material, namely, RNiO2 (R: rare-earth elements). In particular, we estimated the magnetic exchange interaction strength based on magnetic force theory. Our results show that the inter-atomic magnetic couplings are notably reduced by intrinsic hole doping from the blocking fluorite slab which validates the conventional view of regarding Nd6Ni5O12 as a doped case of its infinite-layer counterpart. At the same time, however, the interactions are markedly layer-dependent. The outer most NiO2 layer adjacent to the blocking fluorite roughly corresponds to the 20% chemical doping in the infinite-layer material whereas the inner layers have stronger couplings. The long-range nature and the out-of-plane interactions are also presented. Our results provide useful information to understand this new superconducting nickelate whose intrinsic layer structure is obviously distinctive.