ENHANCED MAGNETIZATION IN BiFeO₃/BaTiO₃ MULTILAYERS: AN INTERFACE EFFECT?

ABSTRACT

We have used pulsed laser deposition to grow BiFeO₃/BaTiO₃ multilayers on SrTiO₃ substrates. The samples are characterized by Reflection High Energy Electron Diffraction (RHEED), Atomic Force Microscopy (AFM), and by X-ray diffraction measurements and modelling. The two multilayers investigated here have modulation periods A = 90Å and 180Å, while the total thickness of 1800Å is the same for both samples. Hence, twice as many interfaces are encountered for the A = 90Å than for the A = 180Å sample. SQUID magnetometer measurements performed on these multiferroic samples show that the magnetization is significantly larger for the smaller wavelength sample thus pointing to a multilayer effect between the magnetic susceptibility and the number of interfaces per unit volume.

Keywords:

• multiferroics
• multilayers
• BiFeO₃ thin films
• X-ray diffraction
• pulsed laser deposition
• antiferromagnetic susceptibility

ACKNOWLEDGEMENTS

This work was partially supported by the EU within the 6th Framework STREP “MULTICERAL” and by the DFG within Sonderforschungsbereich 491.