Antiferromagnetism in Ni-Based Superconductors

TL;DR

This study reports the synthesis of Nd0.8Sr0.2NiO2 thin films and provides evidence of antiferromagnetic order, which is crucial for understanding the superconductivity mechanism in Ni-based superconductors.

Contribution

It demonstrates the existence of antiferromagnetic order in Nd0.8Sr0.2NiO2 thin films, a key insight into their superconductivity mechanism.

Findings

Large exchange bias effect observed

Antiferromagnetic order evidenced by X-ray magnetic linear dichroism

Superconductivity in thin films from 8 to 40 nm

Abstract

Due to the lack of any magnetic order down to 1.7 K in the parent bulk compound NdNiO2, the recently discovered 9-15 K superconductivity in the infinite-layer Nd0.8Sr0.2NiO2 thin films has provided an exciting playground for unearthing new superconductivity mechanisms. In this letter, we report the successful synthesis of a series of superconducting Nd0.8Sr0.2NiO2 thin films ranging from 8 to 40 nm. We observe the large exchange bias effect between the superconducting Nd0.8Sr0.2NiO2 films and a thin ferromagnetic layer, which suggests the existence of the antiferromagnetic order. Furthermore, the existence of the antiferromagnetic order is evidenced by X-ray magnetic linear dichroism measurements. These experimental results are fundamentally critical for the current field.