Self-assembled BiFeO3-CoFe2O4 via aqueous chemical solution deposition

Magneto-electric multiferroic thin films are characerized by  ferroelectric and ferromagnetic order in a same phase, and have great potential in electronic devices.[1] Perovskite BiFeO3 (BFO) and spinel CoFe2O4 (CFO) are... [ view full abstract ]

Magneto-electric multiferroic thin films are characerized by  ferroelectric and ferromagnetic order in a same phase, and have great potential in electronic devices.[1] Perovskite BiFeO₃ (BFO) and spinel CoFe₂O₄ (CFO) are two immiscible phases which are interesting due to the coexistence of resp. ferroelectric and ferromagnetic properties and observation of magneto-electric coupling between them. Several methods were employed in the synthesis of BFO-CFO multiferroic composite thin films. In this work, self-assembled BFO-CFO composite thin film was prepared via aqueous chemical solution deposition method.[2] A mixture of BFO and CFO precursor solutions were spin coated on Pt/Ti/SiO₂/Si substrate and crystallized at 600˚C for 1 hour in a dry air atmosphere. The thermal decomposition temperature was derived from thermal analysis of the BFO-CFO precursor gel. XRD pattern of BFO-CFO composite thin film reveals the presence of perovskite and spinel structure. The formation of crystalline CFO and BFO phases at 600˚C was studied by means of XRD and Raman spectroscopy, showing that both perovskite BiFeO₃ and spinel CoFe₂O₄ phases are present in the BFO-CFO composite thin film. The morphology and film thickness of BFO-CFO composite thin film was analysed by SEM and showed an average film thickness around 100 nm. In future research, the ferroelectric, ferromagnetic and magneto-electric properties will be measured for the composite thin films.

[1] Schmid, H., Multi-ferroic magnetoelectrics. Ferroelectrics 1994, 162 (1), 317-338.

[2] Pavlovic, N.; D’Haen, J.; Modarresi, H.; Riskin, A.; De Dobbelaere, C.; Van Bael, M. J.; Temst, K.; Hardy, A.; Van Bael, M. K., J. oMater. Sci., 2015, 50 (13), 4463-4476.