Synthesis of infinite-layer LaNiO2 films by metal-organic deposition

TL;DR

This paper demonstrates a straightforward method to synthesize infinite-layer LaNiO2 thin films using metal organic decomposition, revealing their metallic nature but no superconductivity.

Contribution

It introduces a novel, simple thin-film synthesis technique for LaNiO2, a rare Ni1+ oxide with potential relevance to high-Tc superconductivity.

Findings

LaNiO2 thin films can be synthesized easily via metal organic decomposition.

LaNiO2 exhibits metallic behavior without superconductivity.

Thin films facilitate oxygen diffusion, aiding synthesis.

Abstract

We report the synthesis of infinite-layer LaNiO2 thin films by metal organic decomposition. Our work is aimed to synthesize perovskite-like oxides with 3d9 electronic configuration, which is common to high-Tc copper oxides. The 3d9 configuration is very rare in oxides other than cuprates. Ni1+ oxides, even though Ni1+ is an unusual oxidation state, may be one of very few candidates. One example of the Ni1+ phases is infinite-layer LaNiO2. The bulk synthesis of LaNiO2 is difficult, but we demonstrate in this article that the thin-film synthesis of LaNiO2 by metal organic decomposition is rather easy. This is due to the advantage of thin films with a large-surface-to-volume ratio, which makes oxygen diffusion prompt. Resistivity measurements indicate that LaNiO2 is essentially a metal but unfortunately with no trace of superconductivity yet.