The origin of the dual ferroic properties in quasi-centrosymmetrical SrFe12-xInxO19 hexaferrites

The local crystal/magnetic structures of the SrFe12-xInxO19 solid solutions (x = 0.1; 0.3; 0.6 and 1.2) were investigated using neutron powder diffraction. The measurements of the electric polarization for all investigated samples were carried out as a function of the external electric field. The presence of the ferroelectric and ferromagnetic ordering (dual ferroic ordering) in the SrFe12-xInxO19 hexaferrites at 300 K was found. This appearance contradicts to the conventional opinion describing their crystal structure (centrosymmetric space group P6(3)/mmc (No. 194)). The reason for the existence of a spontaneous polarization (nonzero dipole moment) in the SrFe12-xInxO19 hexaferrites continues controversial. The crystal structure of the hexaferrites was considered both the centrosymmetric P6(3)/mmc and non-centrosymmetric P6(3)mc space groups. This fact made it possible to find a connection between the emerging dipole moment and not equal distortions of the neighbor oxygen polyhedral. The nature description of the nonzero dipole moment formation in a quasi-centrosymmetrical system of the In-substituted SrFe12-xInxO19 hexaferrites was presented based on the neutron diffraction data. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The local crystal/magnetic structures of SrFe12-xInxO19 solid solutions were investigated using neutron powder diffraction, revealing the presence of ferroelectric and ferromagnetic ordering. The existence of a nonzero dipole moment in SrFe12-xInxO19 hexaferrites remains controversial, with a possible connection to unequal distortions of neighbor oxygen polyhedra. The formation of the nonzero dipole moment in In-substituted SrFe12-xInxO19 hexaferrites was described based on neutron diffraction data.