Hydrogen induced electronic transition within correlated perovskite nickelates with heavy rare-earth composition

Although the hydrogen induced electronic transition within the perovskite family of rare-earth nickelate (ReNiO3) beyond conventional semiconductors was recently discovered, the existing research stays at ReNiO3 with light rare-earth compositions. To further extend the cognition toward heavier rare-earth, herein we demonstrate hydrogen induced electronic transitions for quasi-single crystalline ReNiO3/LaAlO3 (001) heterostructures, covering a large variety of the rare-earth composition from Nd to Er. The hydrogen induced elevations in the resistivity of ReNiO3 (RH/R0) show an unexpected non-monotonic tendency with the atomic number of the rare-earth composition, e.g., first increases from Nd to Dy and afterwards decreases from Dy to Er. Although ReNiO3 with heavy rare-earth composition (e.g., DyNiO3) exhibits large RH/R0 up to 107, their hydrogen induced electronic transition is not reversible. Further probing the electronic structures via near edge x-ray absorption fine structure analysis clearly demonstrates the respective transition in electronic structures of ReNiO3 from Ni3+ based electron itinerant orbital configurations toward the Ni2+ based electron localized state. Balancing the hydrogen induced transition reversibility with abruption in the variations of material resistivity, we emphasize that ReNiO3 with middle rare-earth compositions (e.g., Sm) are most suitable in catering to the potential applications in correlated electronic devices.