Magnetic and dielectric properties of Aurivillius phase Bi

The magnetic and dielectric properties of Bi4.2Nd0.8Ti3Fe0.5Co0.5O15 are investigated by using the measurements of magnetization and dielectric constant. The sample is ferromagnetic with the Curie temperature of 428 K. And the remnant magnetization Mr is 0.5 emu/g, which is two orders of magnitude higher than Mr of Bi5Ti3Fe0.5Co0.5O15. The ferromagnetism in Bi4.2Nd0.8Ti3Fe0.5Co0.5O15 can be ascribed to spin canting of the Fe-based and Co-based sublattices via Dzyaloshinskii-Moriya interaction. Both the dielectric constant and dielectric loss have the characteristics of relaxation, and the activation energy turns out to be 0.658±0.013 eV