Electronic structure and magnetic properties of higher-order layered nickelates:

The recent discovery of superconductivity in Sr-doped , with a critical temperature of 10-15 K, suggests the possibility of a new family of nickel-based superconductors. is the member of a larger series of layered nickelates with chemical formula (, Nd, Pr; ). The member has been experimentally and theoretically shown to be cupratelike and a promising candidate for superconductivity if electron doping could be achieved. The higher-order and 6 members of the series fall directly into the cuprate dome area of filling without the need of doping, thus making them promising materials to study, but have not been synthesized yet. Here, we perform first-principles calculations on hypothetical and 6 structures to study their electronic and magnetic properties and compare them with the known and materials. From our calculations, we find that the cupratelike character of layered nickelates increases from the to the members as the charge transfer energy and the self-doping effect due to R- bands around the Fermi level gradually decrease.