Nickelates with different valence states of the Ni ions are increasingly becoming the focus of cutting-edge research in solid-state physics. Recent discoveries of superconductivity in thin films and bulk crystals have fueled the synthesis and investigation efforts of these compounds. Achieving stabilization of the Ni3+ valence state in LaNiO₃ requires high partial pressure of oxygen for successful synthesis. A recent study from Stuttgart presents the methods and results of growing large LaNiO₃ crystals using the HKZ-300 furnace at 150 bar oxygen pressure and their subsequent transformation into millimeter-sized LaNiO₂ crystals. The resulting samples were characterized using various techniques, providing insight into the magnetic and electronic properties of this elusive compound.

https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.7.014804