Ferroelectric Properties of Bi_1.1Fe_1-xCo_xO₃ Thin Films Prepared by Chemical Solution Deposition Using Iterative Rapid Thermal Annealing in N₂ and O₂

Abstract

Ferroelectric Bi 1:1 Fe 1Àx Co x O 3 (BFCO) thin films with x ¼ 0 { 0:3 have been prepared on Pt/Ti/SiO 2 /Si substrates by chemical solution deposition (CSD) using iterative rapid thermal annealing (RTA) in nitrogen and oxygen. The crystallization of the rhombohedral structure of BiFeO 3 (BFO) is observed clearly in all thin films, and a monoclinic Bi 2 O 3 phase is also observed and is markedly larger in Co-doped BFO thin films than in BFO thin films. An electric field of 2 MV/cm is applied to the Bi 1:1 Fe 0:9 Co 0:1 O 3 thin film annealed in nitrogen at 520 C without dielectric breakdown, but its polarization versus electric field (P-E ) hysteresis loops are not saturated owing to its high leakage current density. The Bi 1:1 Fe 0:8 Co 0:2 O 3 thin film prepared at 520 C in oxygen shows a very good saturation of P-E hysteresis loops at room temperature (RT) at the low leakage current of about 8:7 Â 10 À3 A/cm 2 under a high electric field of 1.5 MV/cm. The leakage current at a low electric field may be Ohmic emission at any temperature; however at a high electric field, it may be attributed to tunnel emission at 80 K and Schottky emission at RT.

Observation of 57Fe-Enriched BiFeO3 Thin Films Using Mössbauer Spectroscopic Microscope

“…In the case of nondoped BFO thin films, the number of reports about well saturated P-E hysteresis loops at room temperature is still few. 4,8,9,16) The BFO-based thin films, which are Mn-doping, 6,8,34) the substitutions of Bi and/or Fe ions, 6,12,13,35) and the solid solution with other ferroelectrics such as PbTiO 3 , 34) have also showed the saturated loops at room temperature. However, their P r values were inferior to those of nondoped BFO thin films.…”

Sintering behavior and physical properties of Bi0.5(Na1–xKx)0.5SnO3 lead-free ceramics

“…Therefore, developing lead-free ceramics and thin film with piezoelectric and ferroelectric properties is of great importance [4][5][6][7][8][9][10][11].…”

Fabrication and Electrical Characterization of Lead-Free BiFe0.91(Mn0.47Ti0.53)0.09O3–BaTiO3 Ceramics

“…BiFeO3 (BFO) thin films have been reported to show excellent ferroelectric properties due to the compressive stress imposed by the bottom electrode, which has a smaller lattice constant than that of BFO [11][12][13][14][15][16][17][18]. However, the piezoelectric properties of BFO bulk ceramics are not consistent in many reports and are very sensitive to process conditions and impurities because the volatilization of some reactants leads to second phase formation and nonstoichiometry [14].…”