Infinite layer nickelates

Main researchers: Claribel Dominguez, Jennifer Fowlie, Marios Hadjimichael, Adrien Waelchli

Nickel appears right beside copper on the periodic table so when the high temperature superconductivity in curates was discovered, the concept that the same property might exist in nickelates was introduced. After a decades-long search that produced all kinds of fascinating studies, superconductivity was discovered in nickel-based oxides [1]. This new family of superconductor have the "infinite layer" structure and are hole doped. They are synthesised in an unusual way, by first growing thin films of perovskite nickelate and then removing a third of the oxygen to leave behind square planar NiO4 planes. This method is known as topotactic reduction [2,3].

[1]. D. Li et al, Nature 572, (2019)

[2]. M. A. Hayward et al, J. Am. Chem. Soc. 121, (1999)

[3]. M. Kawai et al, Appl. Phys. Lett. 94, (2009)