Study of the intrinsic inhomogeneous electronic and local structure in bilayer and trilayer superconducting nickelates

Layered nickelates, including bilayer La3Ni2O7+δ and trilayer La4Ni3O10+δ, have recently emerged as promising high-temperature superconductors due to their structural and electronic similarity to cuprates. The coexistence of superconductivity under high pressure with competing charge and magnetic orders makes these systems a compelling platform for studying competing phases in quantum materials. Microscale inhomogeneities in oxygen content, electronic density, and lattice distortions are believed to strongly influence density-wave phases and superconductivity. As such, in this project, we propose a nanoscale-resolved study of these effects using nanofocused X-ray spectroscopies. Systematic Ni K-edge nanoXRF and nanoXAS measurements on single crystals with varying oxygen stoichiometry, performed at 80 K and 300 K, will probe the role of apical oxygen vacancies, interlayer coupling, and local lattice distortions across the charge density wave transition. The results will clarify the inte