Multiorbital Anisotropy and Magnetic Excitations in Trilayer Nickelate Pr$_4$Ni$_3$O$_{10}$
Rare-earth substitution strongly modifies the structure, metallicity, and superconducting behavior of Ruddlesden-Popper (RP) nickelates, but its impact on their magnetic interactions remains unclear. Here, we combine x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) to resolve the multi...