Effect of Mn doping on magnetodielectric properties of polycrystalline BiFeO3 ceramics

This report reveals the room temperature magnetodielectric effect of polycrystalline BiFe0.8Mn0.2O3 ceramics. Structural analysis shows that the additional phases of BiFe0.8Mn0.2O3 are suppressed and compared with bare BiFeO3. The difference in dissociation energies between Mn-O and Bi-O bonds traps the motion of oxygen ions and reduces the grain size of BiFe0.8Mn0.2O3. Mn-doped BiFeO3 samples exhibit a weak ferromagnetic response because of the effect of Mn in the Fe site which uncurls the spiral spin ordering by altering the canting angle. Additionally, Bi vacancies give rise to charge compensating oxidation of Mn3+/ Mn4+ which causes the ferromagnetic weaker. BiFe0.8Mn0.2O3 shows an improved dielectric permittivity compared to BiFe0.9Mn0.1O3 and BiFeO3 respectively. The magnetodielectric coupling coefficient of BiFe0.8Mn0.2O3 ceramic at 6 kOe and 1 MHz is determined to be 4.64%. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This report investigates the room temperature magnetodielectric effect of polycrystalline BiFe0.8Mn0.2O3 ceramics. Mn-doping results in weak ferromagnetic response due to changes in the spiral spin ordering. Bi vacancies cause charge compensating oxidation of Mn3+/Mn4+, leading to weaker ferromagnetic properties.