Layered palladates and their relation to nickelates and cuprates

We explore the layered palladium oxides La2PdO4, LaPdO2, and La4Pd3O8 via ab initio calculations. La2PdO4, being low spin d8, is quite different from its high spin nickel analog. Hypothetical LaPdO2, despite its d9 configuration, has a paramagnetic electronic structure very different from cuprates. On the other hand, the hypothetical trilayer compound La4Pd3O8 (d8.67) is more promising in that its paramagnetic electronic structure is very similar to that of overdoped cuprates. But even in the d9 limit (achieved by partial substitution of La with a 4+ ion), we find that an antiferromagnetic insulating state cannot be stabilized due to the less correlated nature of Pd ions. Therefore, this material, if it could be synthesized, would provide an ideal platform for testing the validity of magnetic theories for high-temperature superconductivity.