Electronic and magnetic properties of (NdNiO$_3$)/(La$_{2/3}$Sr$_{1/3}$MnO$_3$) superlattices: a DFT+U perspective

TL;DR

This study uses DFT+U calculations to explore how epitaxial strain and interface effects influence the electronic and magnetic properties of NdNiO$_3$/La$_{2/3}$Sr$_{1/3}$MnO$_3$ superlattices, revealing complex magnetic interactions and metallization phenomena.

Contribution

It provides a detailed theoretical analysis of NNO/LSMO superlattices under strain, highlighting the magnetic order and electronic structure changes at the interface, which were previously not well understood.

Findings

LSMO induces minimal structural distortion.

Negligible charge transfer occurs at the interface.

NNO exhibits half-metallic behavior near the interface.

Abstract

The electronic and magnetic properties of NdNiO$_3$ (NNO) thin films are very sensitive to epitaxial strain and to the proximity to ferromagnetic oxides. In this work, we investigate the structural, electronic, and magnetic properties of NdNiO$_3$/La$_{2/3}$Sr$_{1/3}$MnO$_3$ (NNO/LSMO) superlattices under the epitaxial strain of NdGaO$_3$ (NGO) using density functional theory with Hubbard U correction (DFT+U) calculations. Our findings reveal that LSMO induces insignificant structural distortions on the NiO$_6$ octahedra, and that there is a negligible charge transfer between LSMO and NNO. More importantly, we find an intricate magnetic order regarding the interfacial Ni local moments, where we observe a coexistence of ferromagnetic interactions between interfacial Ni and Mn atoms, and antiferromagnetic interactions between inner Ni ions, which results in an overall ferromagnetic coupling across the interface. We also observe the metallization of NNO through the emergence of a half-metallic density of states in the same spin channel as LSMO, which becomes suppressed the further we move away from the interface. Our theoretical findings agrees well with recent experimental data, shedding light on the complex interplay between the induced magnetic order and the electronic properties of NNO.