Improved multiferroic properties and a novel magnetic behavior of Bi0.8La0.2Fe1−xCoxO3 nanoparticles

Bi0.8La0.2Fe1−xCoxO3 nanoparticles of single phase (BLFCOx, x=0, 0.005, 0.01, 0.02) were prepared by a sol–gel method using polyvinyl alcohol as a surfactant. Co substitution at Fe site improved further dielectric properties of Bi0.8La0.2FeO3 nanoparticles in the frequency range below 25 MHz at room temperature. Magnetization at 10 kOe, coercivities, and remanence of BLFCOx nanoparticles increased with increasing Co content. It is interesting that the hysteresis loop of all the BLFCOx nanoparticles presented a wasp-waisted shape. The property can open an important way to design new multiferroic applications of low hysteresis loss in low magnetic fields.