Co-precipitation/hydrothermal synthesis of BiFeO3 powder

Abstract

A coprecipitation/hydrothermal route was utilized to fabricate pure phase BiFeO 3 powders using FeCl 3 •6H 2 O and Bi(NO 3 ) 3 •5H 2 O as starting materials, ammonia as precipitant and NaOH as mineralizer. The synthesized powders were characterized by XRD, SEM and DSC-TG analysis. In the process, single-phase BiFeO 3 powders could be obtained at a hydrothermal reaction temperature of 180 ℃, with NaOH of 0.15 mol/L, in contrast to 200 ℃ and 4 mol/L for conventional hydrothermal route. Meanwhile, the micro-morphology of synthesized BiFeO 3 powders changed with different reaction temperatures and concentrations of NaOH. The Néel temperature, Curie temperature and decomposition temperature of the synthesized BiFeO 3 powders were detected to be 301 ℃, 828 ℃ and 964 ℃, respectively. The hydrothermal reactions mechanism to fabricate BiFeO 3 powders were discussed based on the in-situ transformation process.

Study on the ecological transformation of historical buildings in Tanhualin Block

“…For example, the broken and crumbling architectures with no restoration and utilization value could be used as the landscape structures in the block. Wrecked walls could also generate specific artistic effect through the special design [4]. The two examples of using existing resources indirectly are illustrated in Fig.…”

Characterization of Nano-Structured Multiferroic Bismuth Ferrite Produced via Solid State Reaction Route

“…Bismuth ferrite, BiFeO 3 (BFO), is one of very few multiferroics with a simultaneous coexistence of ferroelectric and antiferromagnetic at room temperature. This material is a proper candidate for memory devices, sensors, satellite communications, optical filters and smart devices [2,3]. BFO is a rhombohedrally distorted perovskite with space group R3c and it has antiferromagnetic ordering with Néel temperature (T N ) of about 370 ℃ and ferroelectric properties with a high Curie temperature (T C ) of about 830 ℃ [2].…”

“…This material is a proper candidate for memory devices, sensors, satellite communications, optical filters and smart devices [2,3]. BFO is a rhombohedrally distorted perovskite with space group R3c and it has antiferromagnetic ordering with Néel temperature (T N ) of about 370 ℃ and ferroelectric properties with a high Curie temperature (T C ) of about 830 ℃ [2]. BFO is mainly produced by conventional mixed oxide ceramic route [3].…”

“…In the solid-state route, after the calcination of mixed bismuth and iron oxides for achieving high purity BFO phase, nitric acid leaching was required to eliminate impurity phases such as Bi 2 Fe 4 O 9 and Bi 25 FeO 40 . This subsequent leaching resulted in coarser powders and a poor reproducibility [2,3]. The present work is aimed to produce single phase BFO by solid stated reaction without subsequent leaching and investigate the influence of Bi 2 O 3 /Fe 2 O 3 molar ratios and calcination temperature on the phase composition, morphology and magnetic properties of BFO particles.…”

Effect of Poly Sodium-p-Styrenesulfonate on the Phase Formation and Morphology of the Hydrothermally Synthesized Bismuth Ferrite Powders

“…Many techniques, such as conventional solid-state reaction [4] , co-precipitation [5] , soft chemical route [6] , hydrothermal route [7,8] and sol-gel process [9] , have been used to synthesize bismuth ferrite powders. Among the methods, the hydrothermal technique is an aqueous-based precipitation route allowing control over the nucleation, growth and aging process.…”