A unique magnetic behavior and dielectric properties of Bi _0.9xLa_0.1Ca_xFeO₃ nanoparticles at room temperature

Ca² and La³ ions co-doped BiFeO₃ nanoparticles, Bi_0.9xLa_0.1Ca_xFeO₃ (BLCFO_x) (x=0, 0.10, 0.13, 0.17 and 0.20), were prepared by a solgel method. X-ray diffraction analysis showed that the average grain size of the prepared samples was in the range of 2419 nm. The lattice structure of the nanoparticles transformed from orthorhombic to cubic with Ca² ions substitution increased. Dielectric properties were measured up to high frequency ∼80 MHz. It was found that the co-doping of suitable amount of La ³ and Ca² ions was helpful to improve the dielectric properties of the samples. Magnetic properties of the samples were improved and all the co-doped samples presented a wasp-waisted hysteresis loop, which was rarely reported in BFO. Characteristics of wasp-waisted hysteresis loops show low hysteresis loss in low magnetic fields, and are helpful to design some multiferroic devices.