Magnetic resonance and magnetization in Fe implanted BaTiO3 crystal

Abstract

© 2014 Elsevier B.V. All rights reserved. The results of investigations of the magnetic properties of Fe implanted barium titanate (BaTiO3) perovskite crystal are presented. It has been revealed that the implantation with Fe+ ions at a fluence of 0.75×1017 ions/cm2 results in the formation of iron nanoparticles with mean size of 5 nm in the implanted surface layer of BaTiO3 substrate. Room temperature magnetic resonance measurements have shown Electron Paramagnetic Resonance (EPR) spectra originated from Fe3+ ions in the BaTiO3 substrate, as well as ferromagnetic resonance (FMR) spectrum from the Fe-implanted surface layer, exhibiting the out-of-plane uniaxial magnetic anisotropy. On the other hand, Vibrating Sample Magnetometer (VSM) measurements of the static magnetization have shown that the composite Fe:BaTiO3 system displays superparamagnetic response at room temperature, and evident ferromagnetic behavior with an easy-plane magnetic anisotropy at temperature below 100 K. The observed magnetic anisotropy is discussed on a model of strong magnetic dipolar interaction between superparamagnetic nanoparticles of iron within the granular composite film formed in a result of the high-fluence implantation.