First-principle study of Sr-doping effect in Nd_1-x Sr_xNiO₂

¹ CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences - Ningbo 315201, China
² Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences - Ningbo 315201, China
³ National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing 210093, China
⁴ Collaborative Innovation Center of Advanced Microstructures, Nanjing University - Nanjing 210093, China
⁵ China Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences Beijing 100049, China

^(a) jiangph@nimte.ac.cn
^(b) zhong@nimte.ac.cn (corresponding author)

Received: 30 April 2021
Accepted: 24 August 2021

Abstract

Sr-doped infinite layer nickelate was recently reported as a superconductor analogous to the layered copper oxides. Previous works revealed that two bands of mainly Nd 5d and Ni 3d characters cross the Fermi level in , whose behaviors under Sr doping are still unclear. We perform density functional theory calculations of supercell to systematically study the evolution of its electronic structure at different doping levels. Our results show that a relative shift occurs between the Nd 5d and Ni 3d bands with Sr doping, deviating significantly from the commonly adopted rigid-band approximation for studying doped compounds. In addition, the relative positions of O-p bands rise with respect to the Fermi level when the Sr concentration increases, resulting in a reduced charge transfer gap. We further estimate the hole concentrations on each band and Hall coefficients, and discuss their relevance to recent experiments.