Multiferroic and magnetoelectronic polarizations in BaFe12O19 system

Coexistence of ferroelectricity and ferromagnetism in one single phase of a solid is of great interest because of the potential application for novel electronic devices. We report on the enhanced ferroelectricity jointly co-existing with excellent magnetic performance in M-type barium hexaferrite (BaFe12O19), which demonstrating a classic electric polarization (P-E) hysteresis loop with full saturation. Two nonlinear current peaks in the I-V curve for polarization switch and giant abnormal change of dielectric constant near Curie temperatures provide sufficient experimental evidences to verify the ferroelectricity of BaFe12O19 ceramics. It holds a large remnant polarization of 55.7 mu C/cm(2) and a suitable coercive field at 441 kV/cm. Two peaks at 194 degrees C and 451 degrees C in the temperature-dependent dielectric spectrum of BaFe12O19 ceramics are considered to be the phase transition from ferro-to antiferro- and antiferro-to para-electric structures. A conventional strong magnetic hysteresis loop was also observed. The influence of oxygen vacancies on the band structure, electric and magnetic properties has been discussed in detail. The magnetically induced E-polarization upon the BaFe12O19 ceramics was achieved in the form of alternating spin current waves. These combined multiple functional responses of large ferroelectrics and strong ferromagnetism reveal the excellent multiferroic features of BaFe12O19, which would bring forth the great opportunity to create novel electric devices with active coupling effect between magnetic and electric orders. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study on M-type barium hexaferrite (BaFe12O19) reveals the enhanced coexistence of ferroelectric and ferromagnetic properties, with classical electric polarization, giant abnormal dielectric constant change, large remnant polarization, and suitable coercive field. Through investigation of phase transitions and oxygen vacancies, the ferroelectric and magnetic properties of BaFe12O19 are verified. The research demonstrates the excellent multiferroic features of BaFe12O19, providing great opportunities for the development of novel electronic devices with active coupling effect between magnetic and electric orders.