Structure and properties of Fe3O4 films grown on ZnO template via metal organic chemical vapor deposition

•We grow single phase Fe3O4 films by MOCVD successfully.•The formation mechanism of ZnxFe3−xO4 transition layer was revealed in detail.•Our study provides a clue to obtain sharp heterostructure interface.

We report the structure and properties of Fe3O4 films grown on ZnO template by metal-organic chemical vapor deposition (MOCVD). The thick and thin Fe3O4 films have been grown with thickness of 500 nm and 50 nm, respectively, to study the quality and interface property of the Fe3O4/ZnO structure. Vacuum annealing has been employed to study its stability. X-ray diffraction measurement revealed the Fe3O4 film deposited on ZnO (0001) layer in (111) orientation with a ZnxFe3−xO4 transitional layer at interface due to Zn diffusion. It is well supported by the observation on Raman scatting that the vacuum annealing improved the structural quality of the remainder Fe3O4 film for thick sample and formed ZnFe2O4 layer for the thin one. X-ray photoelectron spectra employed on the thin sample confirmed that the formation of ZnxFe3−xO4 transition layer at the Fe3O4/ZnO interface. The Fe3+/Fe2+ ratio increases along the growth direction, indicating the diffused Zn atoms prefer to replace Fe3+ in ZnxFe3−xO4. Magnetization curve measurement results are well consistent with the structural evolution for both samples. This study indicates that high-quality Fe3O4 film grown by MOCVD on ZnO template layer is feasible, but the influence of the formed ZnxFe3−xO4 transition layer on spin injection should be researched and even inhibited in the further study.