Metal–organic decomposition growth of thin film metastable perovskite nickelates with kinetically improved quantum transitions

The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates (RENiO₃) triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications, e.g. ocean electric field sensor, bio-sensor, and neuron synapse logical devices. Nevertheless, these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO₃ with flexibly adjustable rare-earth compositions and electronic structures. Herein, we demonstrate a metal-organic decompositions (MOD) approach that can effectively grow metastable RENiO₃ covering a large variety of the rare-earth composition without introducing any vacuum process. Unlike the previous chemical growths for RENiO₃ relying on strict interfacial coherency that limit the film thickness, the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions. Further indicated by positron annihilation spectroscopy, the RENiO₃ grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers, as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis. This effectively enlarges the magnitude in the resistance regulations in particular for RENiO₃ with lighter RE, shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering.