Multiferroic PbFe₁₂O₁₉ ceramics

PbFe₁₂O₁₉ (PFO) powders in hexagonal structure have been synthesized by sol-gel process using lead acetate, glycerin and ferric acetylacetonate as the precursor. PbFe₁₂O₁₉ ceramics were obtained by sintering the PbFe₁₂O₁₉ powders at 1000°C for 1 h. Distorted flaky hexahedron grains are frequently observed in the SEM images of sintered PbFe₁₂O₁₉ ceramics. Large spontaneous polarization was observed in PbFe₁₂O₁₉ ceramic at room temperature, exhibiting a clear ferroelectric hysteresis loop. The remnant polarization of PbFe₁₂O₁₉ ceramic is estimated to be Pr ~ 33.5 μC/cm². The Fe oxygen octahedron in its perovskite-like hexagonal unit cell as well as the shift off-center of the small Fe cation are proposed to be the origin of polarization in PbFe₁₂O₁₉ ceramics. Meanwhile, PbFe₁₂O₁₉ ceramics demonstrate strong ferromagnetism at room temperature. Simultaneous occurrence of large ferroelectricity and strong ferromagnetism in PbFe₁₂O₁₉ ceramics holds promise for its application in new generation of electronic devices as a practical multiferroic candidate in single phase.