Enhanced magnetic and conductive properties of Ba and Co co-doped BiFeO3 ceramics

Abstract

Electrical and magnetic properties of Bi1−xBaxFe1−yCoyO3 (BaxCoyBFO, x=0, 0.1, 0.2 and y=0, 0.01, 0.03, 0.06) ceramics synthesized by modified solid state reaction method were presented and discussed. It is found that Bi-site Ba dopant could result in a transition of crystal structure from rhombohedral to pseudo-cubic symmetry structure, which makes it possible to synthesize BaxCoyBFO ceramics containing more Co ions at Fe site. This demonstrates that the overall composition and crystal structure of BaxCoyBFO can be tailored over a wide range of dopant level. Consequently, BaxCoyBFO ceramics with higher dopant level exhibit strongly modified electric and magnetic properties in comparison to both the parent compound and solely doped BFO. Such as, Ba0.2Co0.06BFO shows higher remanent magnetization (0.93emu/g) and lower coercive field (774Oe), larger dielectric constant, as well as more obvious trend of transition from insulator to semiconductor. The proposed approach suggests a new avenue to create BiFeO3-based multiferroic materials with improved magnetic and electrical properties by co-doping at both A and B sites.