Improved multiferroic properties and a novel magnetic behavior of Bi _0.8La_0.2Fe_1-xCo_xO₃ nanoparticles

Bi_0.8La_0.2Fe_1-xCo_xO₃ nanoparticles of single phase (BLFCO_x, x=0, 0.005, 0.01, 0.02) were prepared by a solgel method using polyvinyl alcohol as a surfactant. Co substitution at Fe site improved further dielectric properties of Bi _0.8La_0.2FeO₃ nanoparticles in the frequency range below 25 MHz at room temperature. Magnetization at 10 kOe, coercivities, and remanence of BLFCO_x nanoparticles increased with increasing Co content. It is interesting that the hysteresis loop of all the BLFCO_x 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.