Towards Metallic Conductivity of Palladium-Oxide Perovskite Nd₂PdO₄

3d transition metal oxide perovskites famously produce many interesting strongly correlated phenomena such as charge-density waves, spin-density waves, strange metallic behavior, and superconductivity. In cuprate and nickelate systems, the strong correlation comes, in part, due to the transition metal orbitals strongly hybridizing with the surrounding oxygen orbitals of similar energy levels. It has been noted that the palladium d-orbitals energy levels lie closer to the oxygen p-orbitals than copper or nickel when in similar systems. Furthermore, the material Nd₂PdO₄ appears to approach an insulator-to-metal transition when electron-doped. We have synthesized a series of compounds from Nd_2-xCe_xPdO₄, Nd_2-xZr_xPdO₄ and Nd_2-xCe_yZr_(x-y)PdO₄ and measured their resistivity from 4K to 250K. These compounds are theorized to have an insulator-to-metal transition at a level of cerium doping above the cerium solubility limit. By using zirconium and cerium-zirconium doping we have achieved a doping level higher than the cerium doping limit, but have not yet observed an insulator to metal transition.