Electronic Structure and Hole Concentration of Ce1-xSrxNiO2 and Nd1-xSrxNiO2 by Density Functional Theory

Abstract

Abstract Recently, superconductivity was discovered in nickelate Nd0.8Sr0.2NiO2. It is predicted to be a cuprate-like superconductor. Cerium, with its natural oxidation states 3+ and 4+, has a stronger effect on the modification of the Ni electronic structure near the Fermi level than neodymium. This work investigates the electronic states and the charge distribution of CeNiO2 and NdNiO2 compounds. Hole concentration and holes doped relative to the parent compound of Ce1-xSrxNiO2 and Nd1-xSrxNiO2 with x = 0, 0.2, 0.33 are calculated. The results shown that the Ni ion in NdNiO2 have half-filled 3dx2-y2 orbital with ionic charge of Ni+, while Ni ion in CeNiO2 is in mixed charges of Ni+ and Ni2+. The undoped CeNiO2 has almost the same hole concentration as that of 20% Sr-doped NdNiO2.