铁酸锌(311)表面结构的密度泛函理论研究

Zinc ferrite (ZnFe₂O₄) nanoparticles were synthesized by atomic layer deposition (ALD). The structure, magnetic and electronic properties of ZnFe₂O₄ were investigated by density functional theory (DFT) and atomic thermodynamics methods; the stabilities of ZnFe₂O₄ (311) surface with six different terminations were considered and the surface energies were related to O and Zn chemical potential corresponding to environment. The results indicate that bulk ZnFe₂O₄ has a normal spinel structure; it is an antiferromagnetic semiconductor with a band gap of 1.91 eV. Only four out of six possible terminations, that is, O₁, O₂, Fe₂ and Zn₂ terminations, can be stable within allowed region. In particular, the O₁ termination is stable over a wide range of Δμ_O under Zn-rich conditions (Δμ_Zn= 0 eV), whereas the O₂ termination turns to be most stable in Zn-poor environment (Δμ_Zn= -3.88 eV).