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

Polycrystalline samples of Ba(0.96)Ca(0.04)Ti(0.91)Fe(0.09)O(3) were prepared using a conventional solid state reaction route with different Fe starting precursors (Fe(2)O(3), Fe(3)O(4)). 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 Fe(2+) and both Fe(2+)/Fe(3+) in Fe(2)O(3) and Fe(3)O(4) doped BCT samples. The P(r) and M(r) values have been measured to be 1.34 μC cm(−2), 2.88 μC cm(−2) and 0.0015 emu g(−1) and 0.135 emu g(−1) in Fe(2)O(3) and Fe(3)O(4) doped BCT samples, respectively. The Fe(3)O(4) doped samples exhibit much better M-E coupling (≈22%) as compared to Fe(2)O(3) (≈7%) doped BCT samples. The results obtained hence suggest that Fe(3)O(4) doping in BCT is better suited for multiferroic applications.