Anomalous Enhancement in Magnetization of BiFeO₃ – CoFe₂O₄ Heterostructure Multilayer Thin Films Deposited on SrTiO₃ with Different Orientation

Abstract

The magnetic properties of BiFeO₃(BFO) – CoFe₂O₄(CFO) heterostructure thin films, grown on (100), (110) and (111) SrTiO₃ (STO) substrates by employing pulsed laser deposition (PLD) method, have been studied. The XRD patterns of BFO-CFO multilayer thin films compared with the pure CFO and BFO thin films grown using under identical conditions evidenced that all peaks present correspond to CFO and BFO structure in two separate phases. Micro-Raman spectra analysis also reveals the presence of BFO and CFO in two separate phases in the heterostructures thin films. The anomalous enhancement in magnetization has been observed for BFO−CFO multilayer thin films, relative to pure BFO thin films in all three different orientations. The saturation magnetization for (100), (111) and (110) oriented BFO-CFO thin films are 44, 62 and 80 emu/cc suggesting that (110) is most preferable direction to achieve the magneto electric (ME) coupling effect.

Keywords:

• ME coupling
• Multiferroics
• Raman scattering

Acknowledgments

We gratefully acknowledge the financial support from the DOD Grant W911NF-06-1-0183 and DOE grant DE – FG02 – 08ER46526. M. K. S. is grateful to VGC India for financial support under the major research project (grant #39-869/2010).