Antiferromagnetism in Ni-Based Superconductors.

Due to the lack of any magnetic order down to 1.7 K in the parent bulk compound NdNiO , the recently discovered 9-15 K superconductivity in the infinite-layer Nd Sr NiO thin films has provided an exciting playground for unearthing new superconductivity mechanisms. Herein, the successful synthesis of a series of superconducting Nd Sr NiO thin films ranging from 8 to 40 nm is reported. The large exchange bias effect is observed between the superconducting Nd Sr NiO 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.