Enhanced magnetization in Co and Ta-substituted BiFeO3 ceramics

Cobalt (Co) and tantalum (Ta) co-substituted BiFeO₃ polycrystalline ceramics were prepared by a solid-state reaction and their magnetic and dielectric properties were investigated. Magnetic hysteresis loops were clearly observed in co-substituted specimens and magnetization was greatly improved. The co-substitution decreased the electrical conductivity by six orders of magnitude along with the reduction of grain size. The magnetoelectric coupling was estimated in co-substituted BiFeO₃ by determining the changes of the dielectric constant with an external magnetic field.