Magnetic and dielectric properties of alkaline earth Ca ² and Ba ² ions co-doped BiFeO ₃ nanoparticles

Ca ² and Ba ² ions co-doped BiFeO ₃ nanoparticles, Bi _0.8Ca _0.2-xBa _xFeO ₃ (x=00.20), were prepared by a solgel method. The phase structure, grain size, dielectric and magnetic properties of the prepared samples were investigated. The results showed that the lattice structure of the nanoparticles transformed from rhombohedral (x=0) to orthorhombic (x=0.070.19) and then to tetragonal (x=0.20) with x increased. The dielectric properties of the nanoparticles were affected by the properties of the substitutional ions as well as the crystalline structure of the samples. The magnetic properties of the nanoparticles were greatly improved and the T _N of the nanoparticles was obviously increased. All the Ca ² and Ba ² ions co-doped BiFeO ₃ nanoparticles presented the high ratio of M _r/M from 0.527 to 0.571 and large coercivity from 4.335 to 5.163 KOe.