Electronic structure and magnetism of transition metal X (X = Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn) adsorbed on vacancy defects in stanene: a density functional theory study

Abstract This study systematically investigated the effects of defect stanene and transition metal adsorption on its geometric structure, electronic properties, and magnetism through first-principles calculations. Optimization results indicate that intrinsic stanene exhibits a typical low-curvature hexagonal honeycomb structure with a lattice constant of 4.67 Å and Sn–Sn bond length of 2.83 Å, consistent with literature findings. Following the introduction of vacancy defects, the local geometry of stanene undergoes slight distortion, with the Sn–Sn bond length increasing to 2.87 Å and the bond angle becoming 122°. However, the overall hexagonal structure and low-degree warping remain stable. Further calculations reveal that after adsorption of transition metals (such as Sc, Ti, V, Cr, Mn, etc), spin splitting occurs near the Fermi level in the band structure of stanene, indicating that these systems possess stable magnetic ground states with local magnetic moments of 0.95 μB, 3.34 μB, and 4.73 μB, respectively. The work function calculation results reveal that the adsorption of transition metals effectively modulates the electron emission capability of stanene, with the adsorption of Mn and Co significantly enhancing surface electron emission. Charge density difference analysis indicates that metal adsorption induces redistribution of the stanene surface electronic structure, particularly exhibiting strong electron donation effects upon Mn and Co adsorption. Notably, after Cr defect adsorption, the stanene exhibits an indirect bandgap of approximately 0.042 eV, indicating a transition from metallic to semimetallic states. This provides novel insights for bandgap tuning in stanene materials. The findings offer theoretical support for potential applications of stanene in spintronics, optoelectronic devices, and quantum computing.