Enhanced Multiferroic Properties in Scandium Doped Bi2Fe4O9

Undoped and Sc3+ doped Bi2Fe4O9 nanoparticles have been synthesized using sonochemical method. The phase purity of the samples was checked using powder X-rau diffraction technique. EDS analysis was done to confirm the extent of Sc3+ doping in the samples. The size and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM). The Bi2Fe4O9 nanoparticles show a weak ferromagnetic behavior at room temperature, which is quite different from the linear M-H relationship reported for bulk Bi2Fe4O9. This is mainly attributed to the uncompensated moments at the disordered particle surface resulting from the reduced coordination of the surface spins, arising due to lattice strain or oxygen deficiency. Addition of Sc3+ dopant in varying concentrations in these Bi2Fe4O9 nanoparticles, improves their magnetic as well as ferroelectric properties. The leakage current is considerably reduced and electric polarization increases significantly in case of Bi2Fe4(1-x)ScxO9 (x = 0.1) nanoparticles. Hence it can be inferred that Sc3+ doped Bi2Fe4O9 nanoparticles shows promise as good multiferroic materials.