Tuning stability, reducibility, and properties of AA'BO_3-δ perovskites by cations composition: A first-principles study

The parent compounds of high-T_c superconducting cuprates consists of layers of spin-1/2 cations forming a square lattice with a large in-plane antiferromagnetic coupling. Compounds with similar characteristics have long been searched for with little progress. Here, we use theoretical tools to explore the thermodynamic obstacles to reducing AA'BO₃ double perovskites into their infinite layered AA'BO₂ analogues. The formation enthalpy against decomposition into binary oxides and the oxygen vacancy formation energies computed from density functional theory calculations are presented as a measure of stability; providing insights into the synthesizability of these compounds. Furthermore, we use these calculations as the basis for examining the connection between structural parameters, such as the buckling of B-site layers and the simulated magnetic Neél temperature of promising AA'BO₂ compounds to gain potential insights into the possibility of superconductivity in these materials.