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Description
A comprehensive first-principles study of the electronic structure and magnetic properties of Pt-doped LiFeAs superconductors has been carried out using density functional theory (DFT) within the Quantum ESPRESSO package, utilizing the PWscf code and projector augmented-wave (PAW) pseudopotentials based on the Perdew–Burke–Ernzerhof (PBE) exchange-correlation functional. Platinum doping levels of 12.5%, 25%, 50%, and 100% were systematically investigated to assess their influence on the electronic and magnetic behavior of LiFeAs in non-magnetic (NM), ferromagnetic (FM), and antiferromagnetic (AFM) configurations. The computed band structures, total and partial densities of states (DOS and PDOS), and site-projected magnetic moments reveal that Pt doping causes notable redistribution of electronic states near the Fermi level and progressively suppresses magnetic ordering. In the pristine compound, Fe atoms exhibit magnetic moments of approximately 1.76μB in the FM state and 1.58μB in the AFM state, confirming significant spin polarization and the energetic favorability of AFM ordering. Upon Pt substitution, the Fe magnetic moments are reduced, and Pt atoms contribute negligibly to the total magnetism (<0.05μB), consistent with their closed d-shell character. For NM configurations, the density of states at the Fermi level, N(EF), decreases from 5.08 to 4.12 states/eV as the Pt doping level increases from 12.5% to 25%. In FM and AFM configurations, N (EF) values further drop to 2.10 and 1.74 states/eV, respectively. This reduction in N(EF) with increasing Pt content implies a weakening of the superconducting pairing channels, suggesting a suppression of superconductivity. Although the observed trends in DOS provide indirect but valuable insights into the interplay between electronic structure, magnetism, and
superconductivity. These findings offer a theoretical foundation for tuning the magnetic and electronic properties of Fe-based superconductors via Pt doping and pave the way for future investigations incorporating explicit superconductivity-related calculations.
