Unravelling the key aspects for the reliable synthesis of superconducting nickelates

Superconducting materials are able to carry electricity without shedding energy loss only below a specific material’s critical temperature (TC), which is, for all the superconductors discovered to date, far away from ambient conditions. Further, the physical mechanism under the superconductivity is still poorly understood. Thus, the researchers are continuously in search of new superconducting materials. In 2019, a new family of superconductors was discovered in layered nickelate compounds, a structure called “infinite-layer”, with TC~10-15K. This ground-breaking discovery has given rise to an entirely new realm of research whose progress has been impeded by the complicated synthesis process of the materials. The two-step synthesis requires to start from a high-quality parent phase and then perform a chemical reduction to selectively remove one third of the oxygen atoms of the structure. In a paper recently published in Advanced Science we shed light on the key ingredients to attain superconducting thin films and the importance of the combined optimization of both steps of the synthesis. Our results will contribute to improve the synthesis of these compounds and will hopefully encourage more research groups to synthesize superconducting films, scarce to date, pushing forward the experimental research in this nascent field.

Araceli Gutiérrez-Llorente, Aravind Raji, Dongxin Zhang, Laurent Divay, Alexandre Gloter, Fernando Gallego, Christophe Galindo, Manuel Bibes, Lucía Iglesias
Towards reliable synthesis of superconducting infinite layer nickelate thin films by topochemical reduction
Adv. Sci. 2309092 (2024)