Doping evolution of the electronic structure in RENiO₃

Rare earth nickelates (RENiO₃) exhibit metal-insulator transitions accompanied by the appearance of charge and spin order, at times concurrently. The understanding of the evolving ground state in these materials is hindered by the existence of multiple competing orders which are further coupled to various kinds of local perturbations (strain, defects, disorder). Very recently, control of carrier doping by means of oxygen stoichiometry has been achieved in RENiO₃, presenting an opportunity to study the broader electronic phase diagram of these systems. In this talk, I will present our recent soft X-ray spectroscopy, resonant scattering, and photoemission microscopy experiments on both pristine and electron doped RENiO₃. Our results reveal the doping evolution of the electronic structure in RENiO₃.