Abstract: 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 △μ_O under Zn-rich conditions (△μ_Zn=0 eV), whereas the O₂ termination turns to be most stable in Zn-poor environment (△μ_Zn=-3.88 eV).