Role of (La, Gd) co-doping on the enhanced dielectric and magnetic properties of BiFeO3 ceramics

The effect of the La3+ and Gd3+ co-doping on the structure, electric and magnetic properties of BiFeO3 (BFO) ceramics are investigated. For the compositions (x=0 and 0≤y≤0.15) in the perovskite structured LaxGdyBi1−(x+y)FeO3 system, a tiny residual phase of Bi2Fe4O9 is noticed. Such a secondary phase is suppressed with the incorporation of ‘La’ content (x). The magnitude of dielectric constant (εr) increases progressively by increasing the ‘La’ content from x=0 to 0.15 with a remarkable decrease of dielectric loss. For x=0.15, the system LaxGdyBi1−(x+y)FeO3 exhibits highest remanent magnetization (Mr) of 0.18 emu/g and coercive magnetic field (HC) of ~1 T in the presence of external magnetic field of 9 T at 300 K. The origin of enhanced dielectric and magnetic properties of LaxGdyBi1−(x+y)FeO3 and the role of doping elements, La3+, Gd3+ has been discussed.