Magnetic ion oxidation state dependent magnetoelectric coupling strength in Fe doped BCT ceramics

Abstract

Polycrystalline samples of Ba0.96Ca0.04Ti0.91Fe0.09O3were prepared using a conventional solid state reaction route with different Fe starting precursors (Fe2O3, Fe3O4). The Rietveld refined XRD data confirmed the phase purity and tetragonal crystal structure of both the samples. The average grain size measured using SEM was ≈0.40 μm in both the samples. XPS analysis confirmed the presence of only Fe2+and both Fe2+/Fe3+in Fe2O3and Fe3O4doped BCT samples. ThePrandMrvalues have been measured to be 1.34 μC cm−2, 2.88 μC cm−2and 0.0015 emu g−1and 0.135 emu g−1in Fe2O3and Fe3O4doped BCT samples, respectively. The Fe3O4doped samples exhibit much better M-E coupling (≈22%) as compared to Fe2O3(≈7%) doped BCT samples. The results obtained hence suggest that Fe3O4doping in BCT is better suited for multiferroic applications.