Annealing Temperature Dependences of Ferroelectric and Magnetic Properties in Polycrystalline Co-Substituted BiFeO₃ Films

Abstract

Multiferroic Co-substituted BiFeO3 films were fabricated by chemical solution deposition method followed by post deposition annealing at various temperatures. The substitution of cobalt of B-sites for iron in BiFeO3 was promoted at relatively high temperatures. The B-site substitution by cobalt promoted increases in saturation magnetization and spontaneous magnetization. By substitution, leakage current density was suppressed in a high-electric-field region, and ferroelectric hysteresis (P–E) loops became measurable even at room temperature. The optimal annealing temperature for the coexistence of a high remanent polarization and a high remanent magnetization was 923 K having a high B-site substitution ratio of cobalt.

Development of Bismuth Ferrite as a Piezoelectric and Multiferroic Material by Cobalt Substitution

“…Chemical substitutions have also been widely explored to induce a net magnetization in BiFeO 3 . Although there have been many reports on enhanced magnetization by chemical modification, surprisingly, the origin of the magnetic signal is unclear in nearly all cases . This is because macroscopic magnetic measurements cannot distinguish the intrinsic magnetic signal of BiFeO 3 from that of magnetic impurities such as γ‐Fe 2 O 3 .…”

Investigation on CuCa3Ti4O12 Modified BiFeO3‐Based Perovskite Ceramics

“…Because Bi 3+ and Ca 2+ have similar radii, which is the same as Fe 3+ , Cu 2+ and Ti 4+ . Hence, it is deduced that Ca 2+ occupies site A, Cu 2+ and Ti 4+ occupy site B in the solution to form a more stable perovskite structure.…”

Modification in Structural, Electrical and Magnetic Properties of Pr Doped Bismuth Ferrites

“…There are many reports on the doping of transition metal ions such as Co, Cr, Ti, Mn, Zn etc. at B-site (Fe-site) in BFO with the enhance magnetoelectric properties [16,17] . It is observed that the electrical properties of BFO ceramics improved by doping of trivalent La 3 + and other dopants at Bi 3 + site.…”