# Antiferromagnetic correlations in the metallic strongly correlated transition metal oxide LaNiO$_3$

## TL;DR

This study reports the successful growth of large, high-purity LaNiO₃ single crystals and reveals an unexpected antiferromagnetic transition in their metallic state, contributing new insights into the magnetic properties of this material.

## Contribution

It introduces a method for growing large, impurity-free LaNiO₃ single crystals and uncovers antiferromagnetic correlations in their metallic phase, previously unobserved.

## Key findings

- Large, impurity-free LaNiO₃ single crystals were grown successfully.
- An unexpected antiferromagnetic transition was observed in the metallic phase.
- Crystals exhibit metallic properties with high oxygen pressure synthesis.

## Abstract

The material class of rare earth nickelates with high Ni$^{3+}$ oxidation state is generating continued interest due to the occurrence of a metal-insulator transition with charge order and the appearance of non-collinear magnetic phases within this insulating regime. The recent theoretical prediction for superconductivity in LaNiO$_3$ thin films has also triggered intensive research efforts. LaNiO$_3$ seems to be the only rare earth nickelate that stays metallic and paramagnetic down to lowest temperatures. So far, centimetre-sized impurity-free single crystal growth has not been reported for the rare earth nickelates material class since elevated oxygen pressures are required for their synthesis. Here, we report on the successful growth of centimetre-sized LaNiO$_3$ single crystals by the floating zone technique at oxygen pressures of up to 150 bar. Our crystals are essentially free from Ni$^{2+}$ impurities and exhibit metallic properties together with an unexpected but clear antiferromagnetic transition.