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\degree C for 1 hour. 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~21{\mu}C/cm2. The distortion of hexahedron grains as well as the Fe oxygen octahedron in its perovskite-like hexagonal unit cell is 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. 
Guo-Long Tan, Min Wang
cond-mat.mtrl-sci